I have a 2004 F150 lariat taht I would like to lift. I am currently deployed and I am looking to fix it up when I get home.  I want to put about a 6 in lift and put 35's under it.  other than that I really don't know much.  I am still going to be using this on a regular basis so fuel economy is still a factor.  Just curious as to the other stuff that I need to get. IE brakes, any work on the transmission, etc.. Any help would be greatly appreciated.  

Hiya greenbeanie. thank you for standing up at the line for us! keep up the great work, a traction adder or two would be a great addition to your ford. the most important part of any 4x4 is the tires, anything that will help you get more and better traction in your chosen arena will be the most benificial to the truck, the next step after the tires is the tractiona adding devices, next, free up the breathing on your engine.
how flexy do ya want to get? what kind of terrain do you want to play in? how releiable do you want it to be?
to run all around there is gonna be compromises, not a s bad a word as it sounds, it sure is cool to run down to the local mud pit and lock in the traction and fling it all over your buddies! then on tho the pigtrail down outback in 4 low and kinda flexy.
and getting some milage to boot! look in the 4 wheel parts wholesalers www site and drool at the goodies!
ford has factory power parts,superchargers,heads etc, to boost the output a little to oh my God!
Jegs .com has a ford section where they show a 100 horse add on blower!
then you can compete with the 1000 watt stereo in the cab!
happy wheelin!  

Why a 6" lift? you'll need 37's for sure with that.

I just put 325/65/18's (35/13) Nitto Terra Grapplers on my '07 FX4 with only a 2 1/2" leveling kit.  

Not sure I was really just basing off of my buddies truck who has an 05 lariat and I liked the look of it. although 37's could work too. and along that line how big should I go for wheels? no bigger than 18 is what I have been told.  

I don't think that i need to be to flexy, I go snowboarding alot so I end up in the snow, and I am from the NW so we have lots of back roads I like to go down for fishing holes and stuff.  Reliability is pretty big, I don't want to constantly be fixing stuff and or breaking down.  I will check out those websites I do appreciate the help.