I didnt realize you were in a hardcore band till I checked out your band's site.... I checked out some of your songs on HXC. You've kinda got the Bane/With Honor sound.... hardcore with sort of a punk underbelly. I like that
Ok... so now I know that there's another aspect of your band that you have to compete with besides instruments, and that's the screaming of your frontman and whoever else does background.
I think you need to go all-out with something, dude. Its very seldom that I see a hardcore band with a 3-pro.... and when I do, the stage is usually lined with an 810. Personally, I think the 3-Pro sounds better than the 4-Pro, but the 4-Pro and the CL are practically FIXTURES amongst the mainstream hardcore scene, from the shows I've been too.
Personally, I like the sound that Every Time I Die gets. I've seen them 5 times. Their bassist usually has a 4-pro with a BDDI. Usually he's overdriven though, and it sounds like that might not be for you. Althought experimenting is fun
I still like the RMX850 for your rig. Yes its VERY friggon heavey. 38lbs or so. But like you said, you could slice out the 3pro if that was a problem. But.... I really think you need to go a step beyond a BigBlock head.
But I think the CL and an 810 would suit you perfectly too. It just might be too much money. But then again.... I see pictures here from Hellfest and The Continental. BIG, LOUD shows....