The smaller the class, the better. That means you will get through quicker. training resources are limited, and captains in upgrade training get priority over FO's. Once summer hits, they need more of the instructor captains to fly the line, so training slows a bit. Try to get in before summer. But if you do get stuck in training for awhile, you at least get your own hotel room and get paid to hang out in the hot tub at the holiday inn.

As far as open bases for FO's, it is nearly impossible to tell until you are in training. There are at least 20 bases, and people are constantly upgrading and moving around. FO's bid twice per year for a base, in June and December. If you finish training in between those times, they will show you a handful of open bases and you take your pick based on what's currently available. Because there are so many bases, you probably won't get your 1st choice, but will probably be able to at least get something in the region you want to be in (Norteast, midwest, carribean, montana,etc)