If the budget is $800 that opens a lot of doors.
If you aren't carrying it much you could always look at a new H&K VP9. They go for $669 with 3 mags and night sites at four seasons in Woburn.
The FN is a nice gun too. I got to shoot the FNH FNX 9mm not the 45 and i liked it. Not sure if its just a new pistol or a new pistol to Mass but havent heard much feedback on quality?
Then there are always the standard sigs like the p226, p220, 1911 series (e-series or sig 1911), etc.
Beretta 92FS is nice. As someone mentioned above there are pre-ban 15 rounders all over the place for sale. Beretta though you really will struggle to carry. 1911 4.25" commander would be better suited although still large.
Again at $800 you can buy new at that point and still get a really nice gun. You need to decide though if you are really going to carry it. I initially thought I was going to carry my 1911 5" Sig and it was just too much. Then it was an m&p 9c (prior to shield coming out), then went to the ruger SR9C, now finally have both my glock g43 and S&W bodyguard when I need maximum concealment. There are some that carry large frame pistols but I found myself opting to not carry as much when I had larger frame pistols. I carry everyday now with the glock g43 and/or bodyguard.
Just food for thought. If its a range gun, get a range gun. If its a conceal gun, get a conceal gun. You can get a decent blend but you will lose out on one end of the spectrum to gain on the other.
Good luck and let us know what you choose!