They have a simple 15.75khz scan doubler for $92 here: http://www.ambery.com/rgbcgatovgac.html (http://www.ambery.com/rgbcgatovgac.html)
It also takes component input, but no progressive support. They specifically market it towards console and arcade users along with older computer support. (Amiga, Atari ST, Apple IIgs) Looks like they have a few other neat products, but I can't find all that much about them online. Now if only they made this adapter with a DVI output...
sounds nice