This is a great post, and I'll comment on it tonight. Gotta get this project finished right now.
Wow, this probably has to be one of the best topics I've ever read on the forum! But people talk about so many issues that it's hard to follow...
Morris, first of all I admire you for being so open and honest about your problems and issues - even though it's an anonymous forum that took some courage).
I won't even try to equal the quality of the previous posts, which are way out of my league - congrats terp, river (even though you 2 disagree), pelihu, etc - but here's a couple of thoughts anyway (sorry if these points have already been mentioned):
Spending time with your family and privileging life quality over money is very respectable (you could almost be European!
). However, I have a hard time believing that an MBA grad, even when he's working in GM (which is supposedly the lightest option in terms of hours), will be working less than 60 hours per week. I might be completely wrong (please correct me if I am), but I don't see a company paying you an MBA salary for a 9 to 5 job. Therefore you have to have a clear vision on the amount of time you are willing to spend at work (more of that below).
Also, I am the kind of person that thinks that an MBA from a school outside the top 20 (and I'm being large here) is pretty much useless. Might as well read the books. Why lose 2 years of your time and money (don't forget to count the salary you won't be earning anymore) for a school with limited possibilities? I don't know OU at all, but if I were you i would seriously inspect the possibilities that the school offers you in terms of employment. I'm not convinced that they will be able to provide you with the type of salary that you would expect after 2 years of inactivity (even with a free ride). But again, I don't know, and it's something you have to seriously look into.
Finally - and probably most importantly - you have to be very clear with yourself and your wife. Choose a path that satisfies both of you, talk about its consequences (in terms of hours, lifestyle, etc) and stick to it. Nobody should be making sacrifices that they aren't ready to make. I think these kind of decisions should be taken very seriously, without over-the-moon expectations (like earning 120k and being home by 6; unless you're in S&T) and everybody has to understand the consequences; but once a decision is taken that satisfies both of you, everybody has to stick to the plan. It's by far the most important step in the whole process. Much easier said than done though.
With your profile and your expectations, I would look at either part-time (probably your best option all things considered) or full-time with 3 years of sacrifice at work, like Terp (I think) mentioned. In both cases you should be looking at a top 20 school (if you get scholarships more power to you). I personally wouldn't even give a second thought to OU - but that's a personal opinion. Or even, don't do an MBA at all. But that depends on how much you want to change careers / boost your current career (I don't know your background), what potential there is in your current career without an MBA, how happy you are with your job, etc.
One last thing: during the MBA, you'll be home much more than you think. It's not a massive sacrifice in terms of time. It can be if you want to, but it is as busy as you want it to be. You won't be the first guy going for an MBA with a family. However, it's a give-and-take thing: don't expect to go out every night like some students do.
Anyway, sorry for the poor quality of the writing, but I do hope that it helps!
PS: this must be a cultural difference (or an education cost issue), but I really have a hard time understanding the home-school principle: all the (small) benefits that you gain from that are heavily outweighed by the inconveniences IMO (but that's just an opinion from somebody who doesn't know the US of course)