There's a good amount of 320 sims but they may also be getting used by Spirit guys doing recurrents or upgrades (met two guys going for captain upgrades when I was down there). I got the 145 and the 737 for my full motion sims, but they do try to put you in the 320 if that's the airplane you'll be flying. The Spirit and frontier guys in my ATP class did get full motion time in the 320 so you can probably expect to get it. It is based on availability tho, so if all the 320s are full with spirit/american guys, then they'll have to put you in something else.