If you want to do a fixed/ss conversion your best bet is finding a flip flop (fixed/free) rear wheel and just use that. Spacing and redishing a rear wheel is a pain to do and really only works okay. If fixed is really in the plans a true track hub is the best bet. You can sometimes find a used rear wheel for not a lot of money without spending for a new pair. That way you keep the stock stuff still usable in case you wanted to build it up on another bike.
and color always black! Black goes with everything. Color matching often can be great, but if the colors are a little off it looks like crap.