Not sure if they re still made but something like the Nokia 6310 has most of your requirement - no USB/RS port but there's plenty of ways to connect to PC
The 'i' version is triband too if you travel much...
Keyboard not covered but cheap case will protect it well as they re pretty robust, had mine for couple of years now and only replaced previous as it got runover! Simcard and battery still in 100% working order thou!
Try ebay? Good if your careful.
PW