Realistically, id go efi, lower compresion a little, and turbo it. 10:1 compression with about 10psi will surpass your goals, be easier on parts, easier to tune, and deliver better mileage. Your next problem will be the block as you'll be turning up the boost when you start getting greedy. A stock block won't live long at 600hp, even less past that. Running boost and keeping the rpm down will help to a point but it'll always be a stock block.
If your serious about your goals you may want to sell what you have and start from scratch with the parts you need rather than working around left overs.
Btw, when you figure the real price I think you'll reconsider since you have a new baby. Throwing around ten grand is a lot when you have kids to take care of.