u may want a bigger alt too. I guess its not neccessary, i ran 2 T10001's off my stock electrical with 3 batts... but i was dipping bad.
also i forgot, i dont know why people are sayn not to get a btl, go for it, especially off that T20001. But if u have a T20001 why dont u do 2 Q's sealed? it would be louder(in theory) than 1 12 btl.