Ok Virginian, I'm gonna do my best to address what I believe you are asking here. If you're suggesting that the wheels you have your eyes on are a freewheel cassette build without a coaster brake, then that should have no influence on your crank/bb setup. If you are looking to switch from coaster brakes you'll need to set up a rim brake, and in order to do that you'll have to see if your frame will accept any type of brake. beyond that, the bottom bracket conversion has been addressed above, although I have to admit RaleighSport is probably correct about the cost issue. I Would stick with a one piece crank and talk to the guys at that recycle shop about some brakes that will go nicely with your frame and new wheels. I'll bet they've got more than their fair share of cranksets hanging around the shop.