I recommend looking through the main thread section, there are a whole heap of decent samples in there to try out
as for no drum replacement software... manual replacement (you're gonna hate deathcore for this one)
Gates, Compression, EQ... these to add later after you've sorted the samples out you're wanting to use...
nip into Glenn's Acoustic Drums for Metal for anything and everything up until sampling, because you're gonna do better having an awesome sounding set of raw drum tracks in the first place...