I used Tamiya spray paints and had good sucess. I didn't use primer right off the bat, but I would suggest you use it. It's less expensive than the coloured stuff and you will find yourself using many more coats of colour especially on the black plastic.
I also used a pearl clear coat on my truck and was really happy with it. The blue worked really well, and the gold that I used was much more tempermental (both from the spray can and the brushed stuff).
Let me know if you have any other questions and I'll do my best to help... Here's the link to my truck...
http://www.rctruckandconstruction.co...ead.php?t=1187