I think either would work. The specs for the UD wall wart are 12v DC 1250mA output. The UD site says that 1000mA is enough to run a single dog. My concern would be around the voltage selection. They seem to be presets and the jump from 9v to 12v is large. The sweet spot for me is between 10v and 11v which would just not be possible without a rotary dial to select output voltage. If you have the UD travel vvps - then you can select 12v on the power supply and use the vvps to drop it down a bit.