Re: Doom/Death
I'm a huge fan of Opeth, but... I don't think it's a Doom/Death band. It sounds more like Progressive Death Metal, according to me.
Even if not any band success to play like Opeth, you should have a try on Be'Lakor or Cynic. (but here again, it isn't doom/death)
Doom/Death bands I find are close to Opeth are "Novembers Doom" and "The Fall Of Every Season".