Hardware questions.

Its been a while I havent checked all the stuff about computers and I have several questions about notebook...including infos I never knew about.

In Rams, whats the difference between 1 dimms or 2 dimms??

Difference between a WXGA screen and a WUXGA screen?

The comparison between Intel GMA 4500MHD, Quadro NVS 160M and Geforce 9400 GS if I often use several design softwares such as Photoshop, Flash, Illustrator at once and some casual gaming. Plus the difference between express card and pc-card.

So far, I can only find Dell offering lease...I wonder if there's any other company that offers lease and customization without needing to open up a creditcard account with them