The K1EL Winkeyer will do everything you need, and much more. The kit isn't hard to assemble, but you'll need to solder. It will do wonders when connected to a computer, but it's a fully-competent contest keyer (complete with auto-incrementing serial number) in "stand-alone" mode.
There are several other units to look at. MFJ might still make memory keyers, and the Logikey keyers are well-loved.
I just checked the N0XAS "PicoKeyer" spec, and it has several memories _and_ auto-increment serial numbers. The kit (with enclosure) is inexpensive and (from all accounts) easy to build:http://www.hamgadgets.com
. . . What rig will you be using?