Engine swap

LQ4 is cheap. Dirt cheap. Dish pistons already so low compression ratio and would be suitable for mild boost. Iron block is heavier but strong and built properly can handler as much power as you want to throw at it.
LS2 is more money but an easier way to go aluminum block if you want to save ~100lbs off the nose of your car. Aluminum blocks can be made to handle a lot of power also.
What's the budget? And how much power do you really want and how hard are you willing to work/spend to get there? 500HP and 1000HP are both doable but like the difference between a Cessna and the space shuttle.
Good luck either way!

