Here is a link to the intelligent PSU's, they are from a UK site but I'm sure you can get them in the US. Various power outputs to suit what you need
140W Plus Intelligent PSU's
EDIT: 140w may be a bit over kill for the 35W max the AE will draw from the PSU, but they do less power rated ones. Price is roughly the same regardless of power rating. There is no nee to step down after the PSU as the power board is internal on both the AE & ATV2.
One other thing to add is that these intelligent PSU prevent the initial power on "Thump", almost a soft start if you will.