If you can't find an M9A1 look for a 92G-SD. It will be more than $620, I'll warn you now. The G-SD is the version with rail and the decocker, along with the heavier "Brigadier" slide. The FS series is a SAFETY/Decocker. Difference being the G lever returns to fire instead of locking down to safe. Both the G-SD and M9A1 grips are textured different than a standard FS but have the same shape. The Elite IA and some Elite IIs are the Vertec frame with a rail.
If you're looking for a Beretta series with a rail the 90-Two series is the 92 with a polymer frame or the PX4s. the PX4s are closer to the $500 range, have a larger magazine, and are smaller than a 90 series.
The Elites and G-SD are not in producion but can be found, GunBroker has them occasionally. PX4s are all over the place.
I've also heard really good things about the FNP series of pistols. Keep wavering between the PX4 and FNP in 40. Not that I'll afford it any time soon.