need opinions: coilover 4-link for 600hp 2007 F150

i am going to be doing some work on a 2007 F150...a buddy of mine has about 600rwhp in a 2007 f150 and wants to go 4 link in the rear to gain some traction...I know air ride technologies has a kit, but is there anything better for a performance truck??? i could do a custom fabbed setup, but he's trying to keep costs down so if any of you truck chassis guru's could give me some quick advice/opinions it would be much appreciated...btw thanks in advance

pics ?

WOOT! http://vissersrod.com/ford-drag-truck.htm Not a kit but if you have a tubing bender and can weld it is a bad setup

i think he's sold on the air ride kit...ill post some pics when he drops off the truck...im going to be doing some work on his Marauder early next week first so it will be after that... ;)

is this the trilogy truck?