I hear this all the time - fortunately, you have not purchased the car yet - as it will give you a little flexibility.
Depends on the power gains you are after. For 1993-1997 (7th generation Corollas) the predominant stock engines are the 1.6L 4A-FE or the 1.8L 7A-FE. Both have potential - but were designed at the beginning as a fuel efficient versions.
Best way is to swap in a GE version of the engine - 4A-GE, 16 and 20 valve versions are popular, 4A-GZE (supercharged) is another - good donor cars are older Corolla and Celicas. Beware the RWD models - lots of the brakets are on opposite sides compared to FWD. The 4A-G* motors will mount to the 4A-F* and the 7A-F* transaxles with just a few modifications. Nothing is really drop in. To do it right - you would need pretty much a complete motor with all the wiring and plumbing. Plus tack on at least another $1000 for misc parts, gaskets, bolts, mounts, wiring, etc.
If you are doing this as a project, money is available, and you really want a Corolla - then do it. Otherwise - you would save a lot (money, time, headaches) if you just bought a performance oriented car to begin with. Price point-wise, the Celicas and older Supras can be had for the same amount of money. Unless you have to have a Corolla or want to make a sleeper car - an engine swap may fall a bit short performance wise.
I done this with Hondas and have gotten decent results - but with a Corolla, you would be hard pressed to get good numbers without spending some serious dough. How much of a performance gain?- Probably about the same as popping on a turbo, same as Probably be easier to buy a Celica and drop a Corolla body on top of it. But if you enjoy turning a wrench - nothing is more satisfying than doing a big project like an engine swap.
Good Luck.
