Okay, went with a brand spanking new Nvidia 470 card with 1280GB of memory and a 120GB solid state drive. Everything is working very well so far, no hiccups so I'm very happy
Think I finally built something worth performing with. 1920x480 x 3 layers no problem (each layer about 800MB). DXV is running smooth as can be. Will post later when I test more effects. But for now, I'm sure the SSD is helping the most.