98 4.6 to 07 5.4 engine swap

Most people will say its more economical and practical to just leave it a 4.6 and slap a blower on it...

Yep.

However, if one wants a reliable GT500 beater one would need to factor in a built shortblock to the cost...

But since the New Edge cars aren't nearly the porkers their S197 successors are (~3300 lbs versus >3900 lbs at the curb) you don't need to make all that power to get good results. I've seen a stock GT500 put down 420HP at the wheels. To get the same w/p ratio (9.3 lbs/hp) in a New Edge car you'd "only" need 355HP at the wheels -- easily doable on the stock bottom end.

Of course a 5.4 4V GT500 motor has lots more potential out of the box and has stouter bottom end than a stock 4.6 2V but if your intent is similar performance to a stock GT500, just s/c the stock 4.6 and enjoy it that way.

If you do go forged on the 4.6 and get enough blower and fuel, the sky's the limit

^True

Not to mention the 5.4 dohc is gonna add more weight to the sn-95.

I would supercharge it. Unless you really wanted tq then that can be had with an twin-screw, N2O, or even a stroker kit.