hey dude,
i reckon you should get some kings or whitelines, they would be in your budget. I got kings in the front and whitelines in the back of my sv21,( did it myself so all up i paid $200 for the springs)ride feels much better now. lowered 20-30mm. check to see if they stock em, i reckon it would look sweet.
Or give Kmac a call they can make springs to suit your exact needs, if u want cheaper then u can try jumboz they quoted me $128 a pair to make 2" lowered springs to suit my car