Yeah, they record with tube amps (not sure which, could be Engl Savage) and then play with VH140C on tour, although I think they may run stereo with other amplifiers on larger packages judging by pictures I've recently seen. I hope I'll get a chance to drool over some major touring gear on that Devourment show. I haven't seen many quality clips of the Ampeg VH140C either, and it's a completely different amp with an EQ in the loop than it is naked. It definitely doesn't compare to a high-caliber tube amplifier though, and if you're willing to spend a grand or more you would be better off with something else for the sound you're wanting. I would definitely look into Engl though, based on those clips you posted. I still say Fireball 100 but the Savage is an awesome amplifier too, if you can find it within your price range.
I'm a bit of a Dying Fetus fanboy. The rig I'm currently playing is based on what I've seen John with. High output pickups into an Ampeg VH140C with a scooped EQ in the loop, through Vader Cabinets, right now a 2x12 and 4x12, but I'm looking around for a 2x15 to replace the 2x12.