Ok well here is a page with a list of Mobile solutions for laptops http://www.notebookcheck.net/Intel-Extreme-Graphics-2.2179.0.html
Generally how it works is that the desktop version is a bit better/faster than the Mobile version.
for what you are looking at you would be looking at Desktop cards like these. HD 3650, Radeon HD 2600XT, Radeon X1650PRO and GeForce 8600 GT.
Those are all older cards so to bring it up to date you would be wanting something like a HD5450.
Anything that performs above that card would b ea improvement.
let us know what teh specs are for your desktop and we can offer some sugestions.