You don't pick the aircraft, you pick the base. But if you pick LA you'll get the saab, if you pick ORD you'll get the jet, LGA you'll get the jet, DFW you might get either. It's pretty simple.
Also, there's no way in hell that eagle has a 20% washout rate. It's closer to 5%, maybe less.
Also, I'm on the ERJ and I've got a line for next month after getting off IOE in January. That's only 2 biddable months that I was on reserve. So don't pick the saab just to hold a line faster. There are way more valid ways to make the determination.