http://www.matrox.com/graphics/en/gxm/products/th2go/
This will work with your Laptop and give you 3 screens.
But, a Dual Head ToGo would work if your MAIN Monitor is a 24" Widescreen. The 24" will share Hoster and you DJ prgram side-by-side.
Just resize Hoster to the LEFT to get rid of the space that isn't used. Then, open your DJ program and place it, resized, to the right.
This way, 2 Heads will work for you.
I got a 24" Soyo from Officemax for $299. Officemax was running a $100 off at the time.