1. Check buy.com they have usually cheapest or next to it tablets.
2. If you don't want to play with Linux you absolutetly don't have to. Most of device you can get without dabbling with OS guts - especially if you want to use it only to basic things: internet browing, media player, e-book reader, simple notes taking.
3. N800 has two SD slots - each one of them can take 16GB card. In total 32GB