descent converter on the cheap?

I retract my statement of the budget Edge Converters after seeing this:

http://forums.tccoa.com/showthread.php?p=577438

Try some of the usual; Hughes, Coan, PTC, Dynamic. Don't skimp too much here, since your application is a mild one $4-500 will get you a decent off the shelf one.

Read this before you decide:

http://www.hardtail.com/techtips/selectingconverter.html