K.L.
I went through Region IV's teacher certification program last year. I had been teaching in private schools for 8 years so I had plenty of experience to go on. Many private schools can hire you with just a bachelor's degree. You would be highly marketable with the math in your background. Finding higher level math and science teachers is difficult for schools. As for the Alternative Certification program I would recommend Region IV, I have heard some not so great things about some of the other programs, not that they are bad, just more hoops to jump through, etc. Through Region IV I was able to do all my course work online. I never went to a class, I never had to take time from my little ones. I fit in all I needed to on the weekends when they were napping.
It is nice to have all the vacations off with the kids. I have worked the 9 to 5 job and do prefer this. It is stressful at times though. I think that is why teachers need the time off. I would avoid TAKS as well. Especially your first few years. It is very stressful!
You need to make a decision now or you will miss out on the next school year. You could start in the summer and be able to get a job in the fall if you move quickly. Good luck!