Can't help you with the stock but Tapco seems to be a good outfit to deal with.
I have placed a few orders with them and when I received an unsatisfactory item, it was promptly refunded with no hassles.
I've heard good things about the Tapco T6 over on the SKS forums. That was what I was going to do if someone didn't buy the SKS I sold you. Don't forget that you're gonna have to deal with 922r compliance and are prolly gonna have to add acouple US made parts.