Yeah I was going for 5x1P, I read the sticky about the new config possibility.
As for stacking cards, yeah, I was hopping to salvage my current card but I'll probably put it on eBay to finance this.
Another alternative I'm hoping might work would be to use the 5770 to drive my TV since I'd rather pass a single HDMI cable through the wall. The 5870 would drive the work monitors on the other side of the wall.
However looking at the costs involved I might pussy out and just add a 5770 FLEX and do with 3 monitors. In this case, would the original 5770 be able to drive the tv as an external display?
My knowledge is limited to the 6000-series and the 5870 Eyefinity 6. My knowledge before used to be primarily NVIDIA based, so I'm uncertain how AMD handles mixing a 5870/5770 or 5770/5770 flex to drive different setups. It's outside of my knowledgebase.