I think you are a bit high on the hp, probably by about 90 or so.
As far as re-using parts, probably the intake and throttle body.
An unknown cam is just a shot in the dark.
The meter and injectors will be too small.
If money is an issue, buy an explorer engine, sell off the heads and intake, use the shortblock, buy some afr 165's or TW's, a good cam, pro m meter and 24's.
That should get you just over 300rwhp.
While that's not 600hp, i assure you the fun factor over your present parts will go up quite a bit.
Then when you want more, do as Fast driver suggested and slap an S trim on.
U think afr 165's would make that much of a diff. The heads I have now sound the same. I have bigger intake but smaller exhaust valves. Im just thinking that for $1500 is it worth it? I dont know?