When my two kids, 10 and 14 at the time, decided they wanted to learn to dive, I searched for the right people to train them. The lds that I settled on is almost a 3 hr drive form where we live, and I pass by several other (competent, and somewhat less so) lds's, that I could have chosen. None close to us, at all, and I went with the advice of other experienced divers who knew all the regional choices better than I, picking the one requiring the longest drive.
Doing their certifications (in the end both OW and AOW); between class room sessions, pool and open water weekends, certainly required a lot of driving on my part, BUT I have always been extremely happy with that choice. In fact I decided to do training with them myself later, when I decided to update my training, and again when I decided to take Rescue.
Pick the agency and the LDS that you feel most comfortable with. Going some distance, if you must, to learn from an instructor that you feel safe and comfortable is worth the extra effort.
There is a reason you have that alternate air source, as you have already learned, and you responded correctly when you needed to.
Don't wish to start any fires, or step on someone's toes, but IMO, ditch the Spare Air, and learn to use (watch) your gauges and learn your gear. The saying: "Spare Air, when running out of air once on a dive is not enough", really touches on the truth. Not enough air in one of those things to really make a difference at any depth at all. Barring a total failure of your systems, learning to continually monitor your gauges will prevent OOA, and as a new student you should not be diving in situations requiring such crutches, especially ones that can get you in trouble, just when you start to rely on them. My opinion only, of course.