In general, bicycle seats are interchangeable, so if you don’t like yours, swapping it out is easy. If that doesn’t work, many love suspension seatposts like the Kinekt (AKA Body Float) or the Thudbuster.
There’s more to comfort than just the seat, though. Each bike has its own riding position. Again, if you already have a bike, and the standard adjustments don’t do it for you, swapping stems or handlebars might put you in a more comfortable position.
When possible, I recommend test riding a bike before you buy. You might discover any number of things that make one better or worse for your needs.
I’m a Pedego dealer, and comfort is one of the things we’re known for. I know there are Pedego dealers in Canada, but I don’t know about Montreal specifically.
Our most popular bikes come with what we call 48v/15ah batteries, but are technically 52v/14.5ah. Range is largely a function of watt-hours, which can be calculated by multiplying volts x amp-hours, so ours is roughly 750 wh. Different bikes will have different levels of efficiency, but looking at watt-hours is good for rough comparisons.