I put in CRL bunk windows. Awning on the driver side and slider on the passenger side. I did the latter for clearance with the sliding door. Turns out that with the CRL awning there is no clearance problem. I could've easily put awning bunk windows on both sides, and in hindsight wish I had.
I thought that having one slider would be a benefit in that I could leave it open while driving. In practice we never do that. It lets in too much dust (at least where we drive).
Regarding airflow, neither of the windows provides much airflow without the help of another force. Our MaxxFan is in the forward most position and even at the lowest setting (1 of 10), exhausting out, it pulls quite a bit of air thru the bunk windows. If it's hot at night we'll leave the MaxxFan on level one and both bunk windows open slightly. If it's cold the fan is off and both windows are still slightly open.
During the day, in warm weather, we leave both the sliding door and rear doors fully open (we have bug screens on both). In this case bunk windows are far too small to make any difference. If we're at a rest stop or truck stop the doors will be closed (for security), bunk windows open, CRL dual T-vent (behind driver's seat) open, and MaxxFan on whatever setting is needed to create significant airflow (rarely more than 5).
If I were doing it again I would do 2 bunk awnings and the dual t-vent behind the driver, and the fan in the forward most position. I would do more research on brands. All mine are CRL, and I haven't had any issues, but there are more choices now.