Keypad is  included on a lot of 15.6" laptops.  Its a must have for me.  We have had pretty good luck with Toshiba, HP, and Dell.  Have an old IBM that is way too slow but is still going.

3 gig memory minimum.  Any size hd for your needs. Most dual core processors would be fast enough.

Don't like refurbished, get new not old technology.

Here is a good place to look for some good deals.

http://slickdeals.net/forums/forumdisplay.php?f=9