If you want more bolt on stuff, you only have a few options...and no you cannot just do spindles like in the first responder, that is 2wd only.
You have 3" body lift, 4" superlift, 5.5" RCD (discontinued, might be able to find a few kits out there though), Dixon Bros LT ($$$), or go with custom SAS as mentioned above.
Sold:2004 XLT 4x2 Ext. Cab. 3.0 Mods: 3" spindle, AAL, shackle, 32x11.5 on 15x8s, billet grille, clear corners, flow 40 dumped, line-x, CB/PA, traction bars, lil sound system, auto up down windows
Sold:2005 XLT 4x4 Ext. Cab. 4.0 Mods: ProComp lights w/ HID swap on tabs, 32x11.5 on 15x8s, CB/PA, black out heads/corners, lil sound system, cranked t-bars, flow 40 dumped, line-x, shell, bed rug, 06+ tails, metal tail gate handle since plastic one shattered, OHC, Mustang Dome.