Docking, Integrated GPU

[amists]

HI

After research it looks like I am going for a T510 as my next laptop - after struggling with cheap consumer laptops for years. There's a few things I need help with before hitting the 'buy now' button.

1) Does discrete gpu create much more heat than integrated? Heat problems is the one thing I want to avoid. I don't do much gaming or 3d stuff. But I play a little WoW and I like using stuff like compiz, if anyone knows what this is. Can integrated handle this, or is it really basic.

3) Is the integrated graphics one of these systems? http://en.wikipedia.org/wiki/Intel_GMA - which one?

2) Can integrated handle 2 monitors coming off the mini dock? what resolution monitors can I use?

If anyone has any idea, and general thoughts on t510 that would be cool

thanks