In some 12 years or so now : ETrade has only blocked like two or three penny stocks that I tried to buy...ETrade all the way with penny's....most all others have frustrating limitations - and are not letting us Americans live Free and do what we want WITH OUR OWN MONEY lol....
I would say try Etrade or fidelity. I use Scottrade and although I generally don't have an issue, I ran into one I couldn't purchase yesterday because they weren't willing to hold the exhorbitant fees on that security.