metal tone using vst amp rack vs ???

I am trying to get the best melodic heavy metal tone that I can, I have tried free external vst’s but they are a little more limited as far as option’s on the mac, I tried lecto with reverance and eq’d but that was still off a bit. I also started to use the vst amp rack but I cant seem to dial up that tone that I am looking for. I have been able to get some great non-metal tones and there are a lot of great video’s and tutorials out there for that, but I have not been able to really find a good guide for the heavier sound. Yes I realize that a mic’ed amp and cab would be best but I record at home so that is not an option. any advise, links, tutorials or snapshots of the setup you use would be appreciated very much. I am limited to mac only and I have learned the little I know from forums and internet so please bare with me. -To all the helpful people who respond with training and experience thank you for sharing your knowledge.

Have you tried AmpliTube? The free version has the same features as the full version but with a limited number of amp/cab models.

http://www.ikmultimedia.com/amplitubefree/features/

thanks I must have missed your post on my e mail i will give it a shot