I'm from jersey and now live in VT. There are no real fixed shops in central jersey... my friend scott loves fixed gears and works at shrewsbury bicycles right outside red bank (765 rt 35 in Shrewsbury). They can order a bunch of stuff and they're a pretty decent place, as is Freehold Bicycle in Freehold, NJ. NJ drivers hate bicycles.
I'll be back in jersey full time after graduation in May, I'll be destroying the jersey shore with my friends all summer. Biking by the shore is where its at