I used spray paint from Plasti-Cote and Duplicolor. Both make vinyl sprays and fabric sprays. The vinyl paint isn't too bad, and with proper prep work, it should last a while. The only place I have had problems is where my arm rests on the top of the door when I hang my arm out the window, so that gets touched up every now and then. The last time I tried dying seats, I used regular rit dye...bad move. My clothes changed colors for months. I ended up putting towels down, then seat covers. I did use the fabric spray paint on the headliner though and it seemed to work pretty good. Little stiffer than it origionally was, but I don't figure that matters too much on a headliner.
At the bottom of my signature, there is a link to my truck with pictures of the interior. The red is regular paint that I sprayed on in very very light coats. The interior has been like that several years and I have had to touch up some spots on occasion, but nothing major.