You might want to look into a Marshall 1960AX or a 1960TV cab. They both use Greenbacks, but the TV cab is a little bit larger, so it will have a little warmer sound.
I have a Marshall 1960A cab that I changed speakers in (G12T-75's aren't very pleasing to my ears). I put 2 Eminence Governors (similar to Vintage 30's), and 2 Wizards (similar to G12H-30's) in an X pattern, and they sound great! They really warmed the cab up and gave it more punch.
[FONT=Palatino Linotype]Tonja Renee's personal instructor
[/FONT]>HERE'S WHERE I AM NOW<