It also depends on your budget, I haven't seen many STI's under 20k honestly...unless its modded/beat to shit or has high miles, so you have to take that into consideration as well.
But yeah, don't kid yourself about buying an RS if you are even remotely interested in modding the thing.
AWD would be fun, but definitely not necessary for Ohio winters, and yet you would have to suffer with the decreased MPG for the remaining 11.5months that you didn't use the AWD, lol.
I'd get a WRX or bust, or consider the two car thing?
I bought a 98 4dr auto civic that was clean and stock for $2500, I average 33mpg with 50/50 city/hwy driving, and 38mpg all hwy. Then I bought an 88 Mazda RX7 for a toy. Best of both worlds, plus no car payments.