id go with the audi, ive driven a wrx multiple times and driven a couple different audi's and audi is definatly the way to go.
the wrx's feel very slow, steering feel is numb and overall just cheaper quality. i ve got 2 friends with wrx's, both had to replace the transmission, one had to get a new engine, and they seem to have to get fixed quite a bit.
audi's arent exactly amazing for reliability though, but if your smart and look for the right one you will have a very solid car. the b5's (late 90's early 2000's) are known for being unreliable, though the 1.8t is kinda an exception, if you find one that wasnt beaten on and doesnt have a ton of miles, it will probably need very little work. a 1.8t wagon would be a sick car.
the 1.8t i drove seemed quite a bit faster than the wrx's ive driven. dont always go by numbers, car manufacturers know dumb people choose cars based on 0-60 times. so focus on only that instead of giving it good power and acceleration all around. the audi was faster in pretty much every gear and any rpm. plus it handles just as well, has much better feel, its better quality overall, and a better awd system.
also look at their older cars, the audi 90's are tanks and most likely wont give you any problems. and if your looking for a 90, might as well get the coupe 20v.