Well for me personally, riding with a freewheel didn't really prepare me for riding fixed (I did the same thing, went from geared bike to SS to fixed). I just said "fuck it" one day, and flipped the wheel around and went for it. To date, I haven't flipped it back :-) If you only need a rear wheel and you can salvage the tire, Amazon hooked me up for like 60 bucks shipped with this. It's nothing special, but it did the trick and stayed true for a good long time. It's flip-flop if you still want to do the SS thing, and it comes with a 14-tooth cog.