You are asking a lot for a cam change, roughly 100 hp. Ain't gonna happen without some serious changes. Can you reduce car weight? Consider a hydraulic roller cam? Head work?
If you really want to stay hydraulic and gain that much power, you will need to extend the rev range(roller) or stroke it to get the airflow at lower revs to make that much power. There are sure to be guys on hear that will chime in with combos they have built that may meet your goals.