I'm looking to purchase a new amp, and I'm stuck between a peavey 6505, triple x ora 3120. Im in a melodic metal band(sound similar to as i lay dying) and my band practices loud and I need an amp that sounds good LOUD!! The other guitarist in my band has a 6505 and it seems like it might be kinda hard to get the right tone out of it( plus he really doesn't take the time to get the tone right) and it just seems tooooo gainy, and ive seen the triple x and 3120 and they seem to be easier to work and more versitle but are they as loud as the 6505? We both use processors and im about to purchase a digitech rp500 b/c it has a stompbox mode where it lets you use the tone of your amp, I want an amp where I can get a good strong crunchy crisp clean distortion out of it and still have tone and here the note clearly at high volumes!! I want a beast of an amp!!

If someone can please help me with this I'd greatly appreciate it!!!
those other amps will be plenty loud. ask the other guitarist if you can try his 6505 and see for yourself. and try the other options and you can decide for yourself.
The 3120 is a cool amp for sure. It is the predecessor of the XXX.

The XXX shipped with 6L6 power tubes, like the 6505.
The 3120 ships with EL34 power tubes, like the JSX.

I think you should spend some time playing the various amps to figure out which tone you like best. Also, the 3120 head is $999 new. I would seriously consider looking for a used XXX if you go this route as they are the same amp and the XXX looks cooler

What is your budget for said amp and does that budget include a cab? What cab do you have now? What is your closest city, I'll try to find you an amp.
Definitely audition them if you can, and i would recommend buying used.