XFX HD 7850 with 3 monitors

I got a new XFX HD 7850 and currently have it hooked nup to two monitors using DVI-D cables.

From this thread I gather that I can get it to work with 3 monitors

I am not sure on how to best go about this. Looks like I will need a new cable in any case, but it's not clear to me which one I should go for.

My 3 monitors are all the same model (some dell thing) and have DVI-D, DisplayPort and VGA ports. The card has two DVI-D, one HDMI and two mini DisplayPort.

Is it a good idea to keep the two current DVI-D cables and get this mini DP to DVI-D adapter for the third monitor?