Hmmm, let's see what we have....
All these guys do decals, some, like Mike Grant of Mike Grant Designs or Eli Raphael of Albatros do custom stuff on order.
http://69.12.6.178/albatros/index.htm
http://www.camdecals.com/
http://www.drawdecal.com/
http://www.eaglestrikeproductions.com/
http://www.meteorprod.com/enter.html
http://www.mikegrantdesign.com/decals/
http://belcherbits.mondenet.com/
http://www.foxonedecals.com/
http://www.redroomodels.com/
http://my.tbaytel.net/fldecs/index.html
http://www.kitreview.com/reviews/victoryproductionspreviewbg_2.htm