Hello gentlemen,
Three monitor support with radeons typically requires one of the monitors to be powered off of the DisplayPort. I know of the Sapphire Flex which allows you to just use the normal VGA/DVI/HDMI ports to support multiple monitors. I also know that ANY GeForce 600-series card can support this monitor configuration without DisplayPort, provided they have the available ports.
My question to you is this: are there any 7850 (7870 is out of my budget) graphics cards out there which are able to power three DVI/HDMI/VGA monitors without an expensive Active DisplayPort adapter?