I can tell you one you don't want, AmerFrade.
Even though they are one of the biggest players in the field, their execution times suck. Of course, if you want tools for penny stocks, forget it, and their charting is for the birds.
They do offer FreeTrade for an opening price of $5K that is supposed to be better but I haven't used it.
Give me a buzz and I'll tell you how I really feel. :-)
G/L.
Nice idea, Lance.