which *uino board to use?

I'd like to make tool for identifying multiple wires using an arduino "transmitter" board and a laptop or pda(preferrable) "receiver". Basically, I'd like to run a coded signal through up to 10 different wires (each lead is a valve station) at around 12V (I'm pushing signal through 14 gauge wire over 500' sometimes) with a single common.

I'm wondering which board would be the best platform to base this project on. Any suggestions? I'd also like to power the transmitter side with batteries.

Thanks!

If you plan to talk to a PDA you will probably want to stay with a serial *duino