Id get a Vintage Modified Squier Strat, maybe with a humbucker already in it. It should sound great, and some say it plays better than a Mim Strat.
Get the strat, i think its more bang for your buck. Alot of ppl buy standard strats and upgrade them. They also make those with duel coils. I have a standard strat ($400 new), but I'm sure you could get a nice used one for $300.
I'd get a used Strat, or a Classic Vibe Strat/Vintage Modified Squier one, which is really good.

So yeah. You can put a 'bucker in the Strat, and you can't really put a single coil in the Epi unless you get a humbucker sized P90.

But yeah, I'd get the Strat.
Cam Sampbell's my hero
Strat most likely, I have both guitars and they are both great! You can't go wrong.
My Gear:
Gibson Les Paul Studio
Fender MIM Stratocaster
Yamaha Pacifica 112v
Epiphone G-400
Cheap acoustic

Roland Cube 30X
USA Big Muff PI
Dunlop Crybaby Wah GCB-95

Fender American Vintage '62 Jaguar
Fender Crafted in Japan '62 Telecaster
THD Flexi-50 + Vox V112HTV Handwired Cab