I would shoot for a 96-98 same body style, little bit better money/hp ratio.
I wouldnt look for one with intake. that can be bought for cheap. if you can find one with a FULL exhaust that would be best, exhaust is expensive and free's up a nice amount of ponies.
if you could find one with a complete or partial PI swap thats even better.
the 96-98 have a few "performance lacking" things that ford overlooked or didnt care about when trying to get the new motor out.
basically the only/best mods you can do to this car before hitting major power mods, bottles and blowers.
pi cams(any nice aggressive cams)
pi heads( optional, raises compression and only nets like 5-10HP)
nice complete exhaust(gets rid of factor 6 cat midpipe)
tuner with tune( stock tune is a performance SUCKER)
gears(stock gears are 2.73 or 3.27) some nice 3.73/4.10's go a long way.
once you do that, thats about the most power your going to gain from this model year stang, and should only cost about 2K to do all that, on top of the base gt you buy.
I'm not an expert on pushrods, but the 94-95 are pushrods and I know nothing about them, all i know is they dont make anywhere near as much power money wise.
hopefully this helped.