So I have an SE Draft at the moment, regular single speed bike. I'm looking to get a new rear wheel with a flip flop hub and try out riding fixed. (Check out all this fuss.) I found a cheap wheel on eBay from Bikesmiths (Good? Bad?) that comes with a 14t fixed cog and lock ring. It seems like a great deal, but t the same time I'd like to have my 16t freewheel cog on the flip side. Would the chain length difference be significant between a 14t fixed and 16t free cogs? Can I make the tension tight enough just with pulling the wheel back in the horizontal track fork end? (It seems close, each link seems about 2 inches, and 2 less teeth would be about a 2 inch difference, the fork end on my frame is probably little more then 2 inches...so...)

Unrelated question: I'm assuming that buying a new tire with a flip flop hub is cheaper then installing a new hub on my existing tire. Am I right? I'm just guessing it would be 40 bucks for a decent hug, a solid 50 bucks to relace the wheel, and another 20 for a cog and lock ring versus the $65 tire I found complete on EBay. (Besides, having a spare rear wheel will only encourage me to build a new single speed bike!)

Any suggestions are welcome. I'm a broke college student, so lets keep this as cheap as possible!

Thanks!