Just get a set of the canted footbeds for the 390's! Really the only difference and you can get cheaper footbeds than if you bought a completely new binding. I love my 390 Bosses FTR.
Unfortunately I have the older 390s, before they came out with the 2 part footbed, so not compatible with the canting footbeds.
My wife has the 2012 version with them though, I didn't think you could buy just the footbeds. Can you get them from Rome?