The aftermarket carb kits use a different type of rubber for the diaphragms inside the carbs, and other materials of questionable quality. Once you rebuild one with those parts, the settings will never be quite the same as stock, and you’ll wind up chasing either a lean hesitation or a rich bog. It’s usually on the lean side, and I’d venture to guess that aftermarket carb kits fry as many pistons in these things as general lack of maintenance does. Trust me, save yourself the headache and just buy the OEM kit to start with! If you hang around the forum for a few more weeks you’ll see literally dozens of threads pop up with people having bog or hesitation issues, and more often than not, they can be traced back to EBay, Amazon, or SBT carb kits.
Im not sure what it would cost to paint the hull yourself. The gelcoat isn’t cheap, but if you don’t already have a good compressor and spray gun, you’ll spend much more on equipment than you will on paint. Search the forum and you’ll find a few people that have done color changes, but that’s generally beyond what your average recreational rider is going to do in the garage.