Hey Keth! Precious few of us Mac Users around. I'm running on an iMac 27 inch late 2010 model with 12gb Ram and core i5 4 core 2.8ghz.

The main problem with macs atm is the heat dissapation issue. Using the apple ram is the best way to avoid heat build up as their ram is designed for it but the downside is you'll pay through the teeth for it! Especially with something as annoying to find as old mac pro ram.Also, graphics card will always be a limiting issue. Mac seems to dislike having the top end graphics cards compatible with their systems.

If I am correct, your MacPro can handle dual 1gb graphics cards at best? And 16gb DDR2 ram?

Sadly, I'm looking at buying a new computer for Rift boxing as well. I think that this is your best option as well. I've been a loyal mac user all my life and have owned every model of emac, imac, macbook and macbook pro but I am being forced to the conclusion that at present, the best option for a multiboxing computer is a PC.

However, my suggestion would be to wait. Don't try buying now. Wait til the sandybridge processors come out before you upgrade.

Also, inside sources are talking that the only changes to new iMacs and Mac Pros this season are processor and increased GPU options. If the MacPro does get upgrades to both of those (about damn time for the GPU options), I'll be buying one of those.