Forester. You could easily get the forester to be as quick as an sti with $3k and put a bit of suspension work into it as well. Put a vf39 on it and sti intercooler with a 3"downpipe and catless uppipe(if its not already catless). Wont even need to swap the injectors or pump unless you want to max the turbo.
If you want sti'rific suspension drop in the sti springs and struts with a saggy butt spacer from subtle. Upgrade the sways and endlinks and anythimg else you want and have a sweet handling sleeper. You could easily come in under budget and have loads of fun.