I am also the owner of a sony a350, and can tell you that lots of people have had problems using off camera flash with Sony cameras and retaining TTL...
Basically for wireless flash there are 2 options....
Use a Sony flashgun HVL-F36AM or HVL-F42AM or HVL-F56AM or HVL-F58AM... doing this will retain all the usual TTL features as the A350 has a wireless commander mode using the pop up flash, but with the a350 there is no way to turn of the preflash, so this may be a problem.
Use Wireless triggers (possibly FITP has some, if not EBAY) I got some from ebay with a Sony hotshoe connector (otherwise you can get an adapter) , and 2 receivers for 2 flashguns, and use any non TTL flashgun (FITP has some good YongNuo ones and YongNuo are the same people that made my triggers), however as you may have guessed, TTL wont be possible.. so set-up must be done manually!
Whichever option suits your budget and needs!