Delmarr- in reguards to your venting question. A bit bigger is better. you can allways
put a small peice of acrilic over part of the vent to close some off if it is to much airflow. Its harder to creat more airflow if needed witho a fan. I have 3 40 breeder verts I built with sliding glass doors not in use yet along with 5 30 breeders. I think the vent is abot 3-4 inches but I would have to check. I would recomend trying the sliding doors, they rock. Also there is no stress on you hinge. only problem with makeing them is your measurements need to be a bit more precise but I didn't have to much of a problem. My local glass guys are awsome and made it very easy for me. I was actually able to center the track with the trim so one peice of door fits snug inside the trim and the other outside the trim. not even fruit flys can get out.