Congrats on paying off that amount of debt so far! That's a great job!!
I guess I have a few questions regarding the moving/debts:
Would you and your wife have job prospects in Chattanooga? Is there some reason you've picked that (family, used to vacation there, etc) that made you land on that, or is a "threw a dart at a map" situation? (don't get me wrong - Chattanooga is supposed to be a lovely town)
The rental property in another state - is the rent covering the taxes and mortgage payment? If not, can you sell it and at least pay off the mortgage? Cause that is one thing that would bother me personally; hanging onto a property that is a money drain. But I don't do rental property, so probably don't listen to me on that one...
Could you and your spouse easily find a job in the area? Done your research on decent/safe neighborhoods, cost of homes in the area, daycare and relocation costs?
If it was me, I'd stay put and really hit that school loan with everything I've got. I would not want to do a big move like that with 40K earning 4/5% hanging over me. You say that you're currently on track to earn 140K this year... that loan should technically be knocked out in less than a year with that much in earnings (unless you're COL is sky high or you're spending like crazy).
You're going to have much more in expenses than just a house downpayment (which should be at least 20% to avoid PMI) - you need a moving fund, living expenses while you are in transit, emergency funds in case the job situation isn't what you thought, purchases for all the things that come with being a homeowner... that's a whole lot of stuff to plan for, and unless you're a minimalist (making it easy to pack/move) with a job skill that will have people beating down your door, you're going to need to make sure you've got a plan and the funds in place.
So if it was me, I'd sell the rental if it pays off the mortgage and get free of that, stay at the current job/location saving like a fiend and pay off the SL debt and then stockpile a tidy sum so in a year's time, I could do the move at my own pace (making a trip or two to scout the locations and find a house/job). Even a crappy situation is tolerable if you know there's an end date and reason you're staying.
Again, that's just how I'd approach it. I'm sure there's wiser than me that would do it differently.