ATI 5750 3 Screen - what do I need to make this happen

not sure which way you're looking to go as far as displayport ---> hdmi/DVI/Vga, or the other way around, but newegg.com or monoprice.com are two places you can look, they both have displayport adapters

Dell and amazon have a dp to dvi active adapters for $100.

What are your expectations about the resolution and gaming with three monitors on the 5750? I read somewhere that the 5750 was really not powerful enough to drive three monitors for gaming. I thought it was a TGH article but could not find it. I did find this one that had a few comments:

http://www.guru3d.com/article/his-radeon-hd-5750-iceq-r...