Hi,
I'm Chris's roommate from MTU. The TX1 is nice because you can get it with a carrier board that can be quite small. There is a list of boards here
http://elinux.org/Jetson_TX1#Ecosystem_Products. Most of them are ok with a range of input voltage such as 5.5-19.6VDC for the carrier board that comes with the TX1, other boards may vary though. The board doesn't draw much power and is typically under 15W.