The texture gun at Harbor Freight was $20 last weekend (Not sure if it was on sale though)

The thinner you need is called Xylel. You can get it at any hardware store.

'90 Trooper - 2.6L 5-Speed - 1" BL - Custom Roof Rack+2x55watt ProComp - Herculined Interior - Pace Setter Header - Dynomax Super Turbo - K&N - ProComp ES3000 Shocks - Optima Red - MSD 6A - 31" Kumho Mudders - Black Rock Crawlers