Thanks guys for all the advice... I think I will go with both breaks... The reason i don't like front brakes for the winter is for the exact reason Somnambulent said... I've gone down a couple (not many... i do learn from mistakes) from using my front brake in snow, and i'll have to disagree with bostonfixed... it's A LOT easier to recover from your back wheel losing traction than your front.
Oh, and just for the record, I am aware of the reasons for running a front break (i.e. more better than back for making stopping) and i've never fallen from using one under normal (not ice or snow) conditions. I was just curious as to whether it was a stupid idea to run just back brake for a beginner to a fixed gear, since i'm competely unfamiliar with riding one (my bike will be done tonight so this will change

)
Thanks for all the tips... i'm gonna run both for now... and i'm off to put the finishing touches on me bike... i'll be sure to post picks when i can!