SLVRXP

I would'nt hesitate to get a programmer, from what I have read they are really worth the money for these trucks, especially with custom tunes specifically for your application.

Here's a great thread on programmers if you did'nt read it already.

https://www.f150forum.com/f7/tuner-programmers-9161/

I plan on picking up an SCT pretty soon. Gryphon looks like a great unit also.

jdjam

I had the edge for about a year before converting it to a gryphon. I would recommend the gryphon. The edge was definitely better than stock, but the new custom tunes are another step up. These were just on sale at PHP.

Dynamic

To add to skull31's list and give a couple more ideas;

Lights are never a bad idea.
Grill while superficial can change the look of the truck.
Bumpers and or a winch

I'm thinking of getting a gryphon CTS myself...but that whole warranty thing has me scared.

Crossfire660R

i bought a Sniper Tuning System for my 04 f-150 and it made a decent difference. with this system, its a software program that you install on the computer and create your own tunes by answering questions. you get up to 5 tunes on the portable "ecu box" and can make unlimited amounts on the computer. and if you really want, you can fine tune air/fuel mixtures, 3rd gear lockup for dyno runs, etc... VERY flexible system. and many dealers that sell them will send you files to put into your tunes if you cant figure something out.