Well, im currently in what you would generically call a death metal band.. and im running a Marshall JCM 2000 TSL that i bought for 300, with a homemade 2x12 cab with some random eminence and celestion speakers..

Of course the TSL doesnt fit my style, i love it and it sounds great compared to my old Crate glx65, but i have the opportunity to trade it for a peavey 6505 2x12 combo.. will this be worth my time and effort? or should i simply wait later for something like a mesa?

I love a real heavy thick tone that just sounds simply mean.. i hear that a 6505 is a death metal master, but have never actually played one in person, itd be quite a drive for me, will i be dissapointed?
^If that is what you play then I say - yes it is a worthy trade.

As far as other options, yes there are other options so this is really up to you.

There are clips on netmusicians.org if you need help in that dept, and you can use the link in my sig to look up amps and get an idea of what they go for used etc.