If you're not in a big rush, the best way to get a killer deal on a new notebook is to watch
XPBargains.com for a few days/weeks/months. Every so often they'll have a coupon code that'll work for a few hours/days that will get you hundreds off of certain notebooks from HP or Dell. Dell in particular.
I've bought both of my Dell notebooks with codes from XPBargains. The first one was ~$1,800 configured but with coupons it was only about $1k, and the second was about $1,200 configured but was about $700 after coupons.
Your requirement of a serial port may be a bit of a problem. A lot of notebooks don't come with them anymore, especially the lower priced ones. Would your gear work with a USB-to-Serial dongle? That would significantly simplify your search, as everything obviously comes with USB ports.
Good luck!
