3rd monitor issues.....

I have an iMac 24 inch Mid-2007 model. It has a View Sonic 24 inch monitor connected to it. My iMac monitor is leaving a ghost image so I've been told that I can hook up a third monitor and just ignore the iMac monitor and use the 2 attached View Sonic monitors.

Now I'm told that my iMac can't handle a 3rd monitor.

Is there a way around this or is my iMac just to old? He told me that I can only run a 3rd montior if I had the new 27 inch iMac.

I was trying to save some $$ on buying a new Mac right now, which is why I was doing this in the first place.

ANY advice since I can't return the View Sonic monitor I just bought.... 😟

This is the view sonic that I have...

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=60525 09&csid=_61

OR

If I was to buy a mac mini, what kind would I need to purchase that would allow 2 monitors?