Sounds like a job for PC World. Pay them a visit and see what they have to offer. You should be able to walk out with something same day.
Only if you are going to be using it away from mains power do you really need to worry about the processor. Moblie ones should allow the battery to last longer.
AMD will be fine for most people, just look at where the fans are.
Its not always a good idea to use a portable computer on your lap for a long time...has nasty side effects!