im sorry but i cant really help with the metal bands you mentioned, im not really a huge metal head amy more, my favorite metal bands are queensryche iron maiden megadeth and a few others (im sure you can guess the names).

i can offer some advice on the music though. for me personally i think zakk wylde is one of the best metal guitarist out there but to me his music is kinda of boring. once you get past the pinch harmonics and the 'wall-o-sound' his playing is just way too technical and theroitical. if you want to make good metal you need to understand theory and have a very good working knowledge of it, but you need to step away from that and understand that the music your making needs to be imperfect, it needs to sound a little off.

an exercise that might help you out some is to get the tabs/ sheet music for a few of your favorite song. while your listening to the song follow along in the tab and cricle/box the parts of it that give it the sound you like so much. if you do this enough youll see certian 'licks' or other groupings that stand out.

another thing to remember is the metal is about aggression and power, if your going to write a slow song write it slow, dont start out hard and heavy with a great intro and then when it gets to the verse/chorus you slow down and whine and cry into the mic.