im looking to by my second car and looking for something a little faster than my old altima but am looking to spend no more than 10000. I've been looking at possible a 95 3000gt vr-4 and ive been looking for supras but there not easy to find for that price. I was wondering what other cars can compare to the power and speed of these cars for about the same price.

straight line mustang and camaro.

LS1 Camaro/Firebird is going to be your best bet.
Other options:
300ZX TT
Mustang GT/Cobra
LT1 Corvette