Well I've always kinda wanted to do the sr20 in a 200sx. 350whp would be fun. This is just some of the random stuff that I can think of and have heard about or is actually feasible.

FC with a 13b or ls1
Miata with a sbf of ls1
240 with a bb or ls1
crx with a k24
any honda with a k24
Lexus sc/gs 300
TT lexus sc400
Mr2 with a 3vzfe v6 (200 na hp)
turbo z32
...

65 mustang with a rb26 .....

Cavalier with a monster truck engine....

Anything can be done with enough time and money. BUT WE NEED TO KNOW WHAT YOU ARE GOING TO USE THE CAR FOR!!!!!!