I recently got a Gallien Krueger400 RB head. Puts out 280 watts...
I need some cab suggestions. I was thinking of running a 4x10 on top, and a 1x15 on the bottom. I play stuff ranging from Outbreak, Set Your Goals to The Faceless, All Shall Perish. So I'm looking for chunk/tangish...

Another hardcore bassist, I'm not alone!

If you've got the cash, I suggest the 4x10 and/or 1x15 from GK that's above the Backline series. I forget the name right now. Just one of those will be plenty unless you really, really need both. They're around $450 USD each.

The new GK cabs with the gold aluminum cones sound badass as well. I played a 400RB through a 2x10 and 1x15 rig and it sounded amazing. Punchy as well with low end thump. The 2x10 is around $300 USD and the 15" is $400 USD I believe.
-Fender Deluxe Active P-bass (60th anniversary)
-Peavey T-40 (1982)
-Hartke HA-3500
-Aguilar GS 2x12
-GK Backline 2x10