Best site for CD's is Goregiastic Records
See here: http://www.goregiasticrecords.com/
Also if you like hardcore then there is nothing wrong with alot of UK harcore. I love the US stuff from the 90's like Irate, Fury of five, Merauder which is timeless but bands like First Blood etc are all starting to sound the same. Generic break down after break down. Check out Knuckledust, 50 Caliber, Special move, Six Ft Ditch, Prowler etc... Stampin' Ground and most US hardcore bands are weak in comparison.
In terms of death metal or anything else (gore-grind etc..) well there's LOADS to choose from. HateEvent has started a good list but you should also check out Insidious Decrepancy, Devourment, Pus Vomit, Gutteral Secrete, Cephalotripsy, Putrid Pile, Gorgasm, Cephallic Carnage, Soils of fate, Torso F*ck...the list goes on and on...
New Dying Fetus is poor. I gave up on them after "Stop at nothing". Bring back Kevin Talley!