Here's a link (just a sample):
http://www.tigerdirect.ca/applications/SearchTools/search.asp?keywords=monitor+extension+arm
There's plenty more on the web.

Add to that a Dell 2408WFP or a Dell 2709W monitor and for the price of that laptop you were looking at, you can have a pretty speedy quadcore system with 16Gb of ram.

Secret... those two monitors are pretty well regarded in reviews.  For a few days every month, Dell has those on sale on their internet site.  In my neck of the woods (Canada) the 2408 is reduced from $699 to $550, and the 2709 was reduced from $999 to $599 (go figure).  You just have to check every day for the sale.