Fourteen years and 100 pounds ago I was in a similar boat. I wanted to bike to shed the pounds (I was up to 280, which is bad at 5'4"), butt my tailbone was killing me... right up until I switched to a cruiser.
My old conventional 3 speed, cheap Micagi Tahiti NX3:
Even back then I never did anything "stock". Custom cranks, bigger chainwheel, homebrew headlight and battery box...
Far too many bikes assume you're going to use the "crotch rocket" lean forward over the bars position, thus the straight bars and butt floss seats. The combination -- as was stock on my Aventure -- is fine for young healthy riders, but as you get older or have problems that leaning forwards causes neck, shoulder, and even wrist strain no matter how much you try to dial it in.
To that end I've come to HATE straight bars.
The more forward you lean, the more those skinny seats make sense, but something I rarely see discussed is how the farther back and upright you ride, your weight shifts until the narrow seats are pounding your tailbone by spreading the glutes. Butt flossing yourself is not a comfortable ride.
Cruiser bikes are meant for an upright riding position, thus the longer swept-back bars and wider seats. Think about it, is the same part of your body touching the seat when you're leaning way the hell forward as opposed to when sitting upright? Of course not. When leaning forward your weight gets moved to the perineal.
That's the "taint' for those of you who don't know anatomy. As your stance goes more and more upright that gets shifted to the sacrum.
Aka tailbone.
I'm amazed how many "experts" out there seem to scream "narrow seat, narrow seat" or "get your sitz bones measured" without taking into account stance, which completely changes your weight distribution when seated! They're so obsessed with the "aerodynamic position" they thumb their nose at any other notion.
Dialing in a good comfortable ride is more than just seat, it's also bar length and distance. Getting mine adjusted right was a bit of a trick as the cruiser bars got the right angle and width, but because of the frame length I had to get a longer neck to then push it forward. A more intermediate bar would probably have made more sense, but I was working with what I had on hand and could afford.
For now this arrangement:
Black and red with whitewalls... It's just my "thing"
Is working for me, though I feel like the crank could stand to be a bit more forward and/or the front end a bit higher. Using a longer fork / fork adjustment thanks to the double-shoulder set helped a lot too raising the front end about an inch and a half.
The really long neck / stem pushing the cruiser bars forward, whilst retaining their longer width and angle removing any trace of shoulder and wrist pain, further helped by the (cheap) paddle grips.
It can get a little pricey dialing these things in, but the idea of "one size fits all" is always ridiculous, more-so when it comes to ergonomics.
There are so many things that can mess you up. Leaning too far forward for a wider seat, leaning too far back for a narrower seat, bar too wide or narrow for your stance, bar too far forward, back, up, or down. Bar angle at your grip, seat angle, seat height...
Hell the number of people I see where they have the seat too low so they're causing knee and buttocks pain. Though conversely I don't understand the people who have the seat higher than the bars, that cannot be comfortable. My 50-something year old back doesn't bend that way anymore. I don't want the lean the freak forward crotch rocket stance because I'm after a calm comfortable ride on roads and prepared paths.
I have no plans to "send it" down a double-black, do competitive racing, or hill climb challenges... and it often seems like a lot of cycling "experts" lose sight of that; looking down their noses at us more... casual riders.
Not that cultism, elitism, and insular attitudes are unique to cycling. Starts to feel like how in retro-computing the "demo scene" and I get along like sodium and water.
I played around with dozens of seats (blessed be Amazon's no questions returns!) It's funny I tried a nose-less one and that was horrifying. Not from a comfort point of view, but safety. I was shocked how much "balance" comes from that forward protrusion in the seat. Constantly felt like the bike was going to pitch over and I was gonna go flying off it.
Just like swapping out the cranks, chainring and cogsets to best match myself and the motor.
One size fits all fits nobody!
Now, all that said, I've found riding to be very therapeutic for pain. Between diabetic neuropathy, a medication induced parkinsonism thanks to some quack giving me Neurontin off-label, much less a host of prior injuries, I was very quickly becoming unable to ride my old cruiser with any frequency. The e-bike has definitely solved most of the problems I was having in both mobility and remaining strength.
It's actually starting to be a 'problem!" A good hour or two of riding --
now that I have the bike dialed in -- gives me three to four hours of solid pain relief, which makes me keep getting up and going for rides whenever the pain comes back. Thankfully I've got two batteries and two chargers. But it's throwing off my sleep; not good when you also have non-24 sleep-wake disorder.
The leading reason I'm considered disabled. I'm incapable of living a 24 hour day and have to live a 26 hour cycle of an extra hour sleep and an extra hour awake.
I also think my ear-to-ear grin is creeping people out on the paths, it's just so good to be pain-free without resorting to medications.
For some reason I'm now ridiculously paranoid about taking prescriptions. It's even reducing the frequency of my crippling headaches --
caused by a hyperactive ventromedial pre-frontal cortex -- that are so severe I've got a script for Sumatriptan.
Fun medication that one...