If you can't get to microcenter, you're looking at a Pentium G620 (~$65) to G850 (~$88) for your build. that's just the price of the CPU. A decent mobo will run at least $60 on top of that *if* it's a micro ATX. The 4100 outdoes both of them at it's stock speed, and is cheaper than either if you can get to microcenter. NTM, the FX series is unlocked and the 4100 overclocks very well. The Asrock mobo above is also full ATX.
I don't know how much it'll cost you to get there w/o a car, you'll have to calculate that for yourself, then decide if it's worth it.