You can get a "metal" sounding kick out of a normal one by cutting out the mud in the low mids and raising up the high end so it gets that scooped clicky sound. As for snare, keep it nice and snappy with a compressor or envelope, don't let it ring out. Hi hats get mixed pretty low in metal and use mostly the overheads. Just some vague suggestions, they may be of no use to you.