This started out, figuring out away to spend your money LOL
Also to give you good HP gains, with budget plan.
I am not sure on 4.6 2 valve, but 4.6 3value has
RWHP at max 450 without destroying block.
I suspect, likely close to same with yours.
How much money and much HP always helps dictate build.
If 80 to 100 is enough, ( for now) then
5-7 k, 3-4 years and your good to go.
As Marc said, air and tune are key.
Driving will change a little and giddy-up
Except for exhaust sound, bit of a sleeper
when you are pushing 400+hp
This is fun research and as you see, no lack of help, spending your money.