Need modification advice for 4V

Hi all, I'm new to the board and have a delima. I've got a child on the way and one of the cars have to go - between a 98 Corvette or 96 Cobra. Both cars are starting to get boring so it's time to modify but boss says one has to go. The Vette would make more financial sense to sell, however the LS1 is a great motor to build. I can get in the upper 500 horsepower range with a supercharger / heads / cam. But I'm looking for what can be done to the 4.6L 4V to get the same results for the same money and I'm not finding much luck. It seems that the old pushrod 5.0 is the modifiers engine of choice. So what can I do to this motor to get into the 500 - 600 hp range? And would this include a built bottom end (which will ultimately cost more than what I could do to an LS1 to get the same power)?

Thanks for your advice...

I've already got some heads for the LS1 which helps, but you're right about $5-7k for the blower and cam. Figured that's probably what I would end up spending on a blower for the Mustang anyway. Thing is, I can drive the Mustang everyday and throw a baby seat in the back. Can't do that with a Vette. I havn't seen too many people advertising 500+ rwhp with these motors. It that with lowering the compression ratio and adding boost or sticking with a stock bottom end or stock c.p. with lower boost?