Well, another shock question . . . alright!
Is it possible to upgrade the shocks? The answer is . . . Yes!
Do you want to upgrade? Meh . . . maybe
Do you need to upgrade? I would think, not right now as your bike is actually very new.
OK, a word of warning . . .all of this is just my opinion.
While the Mozo FatMan air shock is not the super duper best you can get, it gets the job done for now. Granted, it doesn't carry the status or specs of a FOX, ROCKSHOX, or MANITOU though, if that's what your looking for.
You need to consider several factors before going down this path.
First, the availability of an air suspension fork that is 1 1/8 none tapered. Second, a fork with a wheel clearance to accept a 4 inch wide tire, if you decide to keep the fat tire look. Third, a fork that is configured to accept a 9 inch quick release axle. With just these items to consider, the choices are few but not impossible.
Consider the axle. If a fork with quick release is not available or possible, then a thru axle design is the other choice. But . . . OH wait! The front rim on the RipCurrent is a 9 inch skewer design. That means the entire rim and/or hub needs to be replaced . . . doable, but an additional cost.
The existing Mozo fork has 80 mm of travel. As a general rule, you want to keep within 20 mm of the original spec so as to not throw off the geometry of the bike. That would mean a 100 mm maximum travel fork. OK . . . doable, not a deal breaker.
Next comes . . . $$$. . . COST. If the intent is truly to UPGRADE the suspension, I would say a minimum of $250, and you could go to $999 or higher. Yes . . you can buy cheaper forks on Amazon or Ebay, but we want to UPGRADE, and remember, "You get what you pay for!" Then, unless you have the DIY gene, you will have to get someone or a LBS to do the job for you . . . more $$$.
OH GREAT . . . you just POOPED on my dream! Sorry, didn't mean to do that!
OK . . .OK! You say that, " I don’t do any heavy off road riding but, my
main purpose is a smooth and comfortable ride."
As I see it, the main function and purpose of the shock suspension is NOT necessarily comfort, but to keep the tires in contact with the road surface, much like the shocks on your car. Granted, a side effect of the shocks is they smooth out the ride. When your riding over that washboard surface, you don't want your tires spending most of their time above the road surface.
OH DEAR . . .I want to go left, but my tires are floating in the air like balloons . . NOT COOL!
If a smooth and comfortable ride is what your looking for, a suspension seat post may fill that need better. Units like these:
Kinekt 2.1 - $250
Suntour NCX about $109
Thudbuster LT - between $130 to $150
Thudbuster ST also $130 to $150
While some may say they are kinda pricey for a seat post, they are well made and do the job quite well.
Personally, I wold avoid the cheap seat posts like this:
they are all over Amazon, Ebay, the Big box stores and even some bike shops for $20 to $40.
While they do work somewhat, they are . . . well . . . cheap. Their travel is only linear. Sometimes the stanchion and seat post have or develop play and wobble, or the saddle starts to hunt left and right as you peddle and ride. Another, "You get what you pay for" deal.
Another option is a suspension saddle like these:
Schwinn - about $18
Sunlite Cloud 9 $25 - $30
Serfas $50 - $55
I know, I know! Oh Man . . . those are for old people. Who cares what your kids and friends say! Hey . . . if it works for you . . . GREAT!
I don't know if any of this helped or answered your question, but maybe it will give you and anyone else considering it something to think about.