Re: Build Recommendations
The wheels are usually the least of the concern. I believe the "Columbia 1937" bike is a Huffy, which has like 12ga spokes. Worst case, you'll have to replace the guts of the coaster brake with Shimano components. A whopping $12 venture.
Suspension is not required. Nice, but not required. A good suspension fork if you want one is the monarch springer. I believe you'll need the 1" tube.
Hardware: you're more likely going to need good hardware for the motor kit, and not the bike. Replace all the acorn nuts on the engine with open hex nuts.
At least get a rim clamp brake for the front. You can actually bolt it where the fender bolted to, which you said you won't be using. And buy some kool-stop pads. You'll thank me for that.
The frame looks cool enough. I've considered it, but never pulled the trigger. It doesn't have a welded on rear rack, so you should be in good shape. Search "Huffy nel-lusso" or "Panama Jack". You'll see what I mean. It's essentially a cranbrook with a welded rack, which makes a weak point for the frame. Don't let that discourage you from Huffy bikes. They're good cheap bikes that can hold up to good amounts of abuse. Just make sure you grease the bearings before you ride it.
When you get your 48cc 2 stroke kit, take it apart. All the way. You'll see that there is still metal shavings in the engine! Clean it out. Now that it's fully disassembled, do a gasket match port on the transfers. It helps power so much, and makes it so much smoother.
Above all, enjoy your build!
Never stop wrenching