I have three external CD/RW burners. All are Firewire - USB almost has to be USB 2.0 If you have it - great. Toshiba, Plextor, ADS, and Que! are all good. They are easy to use and, frankly, more reliable than internal IDE models.
With an old Thinkpad, I would get a Firewire PCMCIA card and connect that way. USB 1 is too pokey.