It's better to get a fixed/fixed hub because you can run a freewheel on a fixed mount and a fixed cog on it as you prefer. People mount freewheels on fixed threading all the time with no problem. If you are going to use one side with a fixed cog and one with a freewheel, get fixed/free since they're easier to find. Wheels, there are several wheel sites, but I have not dealt with any of them. All my wheels came from Excel Sports Boulder and Harris Cyclery. Let us know how this all turns out! I like shimano freewheels, too.