Ok my Cab is a 4x12 with vintage 30's speakers in there but they sound IDK old like they need to be replaced a little bit of a pop at louder settings. what is the best replacement speaker for a metal sound.
Speakers shouldn't wear out unless you've mistreated them. If they're blown you can recone them much cheaper than replacing them.
I've heard great things about combining them with celestion G12T-75s in an X pattern.

I'm getting celestion G12T-75 to put in my 2x12 along with a vintage30 myself. This is the combination used in Bogner Uberkabs I think.
WTLTL 2011

Yea, that's the Uberkab setup. Supposedly it sounds amazing. Also, you may wanna throw in two Celestion G12H-30s. Supposedly it really fattens up the sound.