You can, I went that route, but wasn't very happy with the AM whipple tunes, they were significantly off. I ended up taking it to RET for a dyno tune.
From what I understand, the Lund tunes are right on for the whipple.

 

I just ordered mine from American Muscle, should be here by Friday

With the forum discount they were cheaper than Lethal Performance and AM had it in stock ready to ship out. The kit comes with a voucher for a pro-cal tuner and I've heard that the tune it comes with is pretty good.

 

Here's some advice. Buy a beater to drive for a year or so, save some more money and then buy a used 5.0. You will have a much better platform to work with.

 

If you are dead set on having a blown 4.6 I'll sell you mine for 16k.

 

That's not a bad deal at all, especially with all the mods you have!

4.6 FTW!

 

Thank you but i am going to be holding out for a bone stock 08-09 GT, thats performance white and has under 30K miles