Hi Dave,
Sounds like you have done a lot of thinking and planning so far. Having your wife's support and her having a job are two major pluses, IMHO.
I know you'd like to have more background but doing one rehab, where actually you made a profit, is far above many people who quit their jobs without ANY experience whatsoever.
Regarding low (quality) inventory, we're seeing that here in New England, too. Try to get deals via many pipelines as you can - MLS, REOs, bird dogs, wholesalers, marketing/mailings, etc. That way you can feel more comfortable that you'll have more houses available to you to complete your 2013 goals.
If I were in your position, as someone that is still "stuck" in Corporate America, I would look at your situation as the perfect situation to give going full time a try, but that's just my opinion. You could always go back to the 9-to-5 world, if you needed to/wanted to.
Sometimes it's better to regret something you did, rather than something you didn't do.
Good luck,
Steph