The compromise will be between price and weight, once you satisfy the needs of Wireless etc. Get the lightest you can afford....
Ideally the Centrino chipset is best, but for basic "business use", which is what you really need, a Celeron-M is OK. I use one for similar (but Business) and its a good compromise.
Look at the low-end Toshiba range for reliability.
The Toshiba M50 range would be a starting point, (Celeron-M 1.5 GHz) somewhat above your budget perhaps, but Google will tell you what its worth in your area.
Mine has both Wireless and DVD burner, with an additional 256 MB RAM (512 total, which I recommend as minimum) and cost the US equivalent of US$780 before local taxes as an example.
I learnt my lesson on heavier laptops. You get annoyed with the bulk in a very short time.