Hey Cool, I've been making my own decals for years on a color laser printer... well wort the investment if you are doing a lot of decals. You can also print your own using an Ink Jet. Papilo " http://www.texascraft.com/hps/home " has the best quality papers Clear, White, Sticky-back vinyl, or water-slide; Inkjet or laser. If you use an InkJet Printer, you will need to coat the finished decals with Krylon Crystal clear. That's why I bought a color laser.
One caveat; no printer can print "WHITE". If you need white on a clear background go to Callie Graphic at " http://www.callie-graphics.com/airplanes.php " or CFC Graphics at " http://www.cfcgraphics.com/flyingcircus.html ".
Good luck!