yea most hi res are in 512x512, the older stuff is 256x256 and taladrens superlow res is 128x128 but for older video cards 512x512 will kill them, I loaded up my Deadalus class on a Rive TNT M64 8mb card, it was sluggish, shrunk to 128x128 was smooth but very low res. Today I wouldnt worry about peoples video card ram size, everyone should have 128mb or more today. And if you want superres you can always do 2048x2048 ive seen one model with this, but it lagged on my Geforce 6600GT lol.
but where are these turtoials for meshing and applying textures im very curious about them, as ive been tring to learn this stuff