Maybe the only thing I can add is that something does not seem right with the credit score. I work with people that have bankruptcy, foreclosure, collections, and pretty much anything else you can think of under the sun. I would think with your income that there should not be any current delinquencies that would prevent your credit score from going higher. We should be able to shoot your credit score up in 3 month's no problem, but 6 for sure if you want to buy year's end.
I have found not all loan officers know much about improving your credit, but I am here to tell you that unless there is something seriously wrong you don't need to use a special company. A good loan officer is all you need. I have my own loan officer that works with all my credit buyers, and I would be more than happy to refer her over to you. Just get in contact with me.
It is actually a good thing your wife went solo on that duplex, because I believe you can now purchase FHA solo by yourself still. Not 100% certain but it would make sense.
My suggestion would be to talk to a individual that is in credit repair. There are many options they have available to get the score up. If interested give me (Scott Rheinhart 612-281-9990) a call and I can pass along a name and number of one of the best credit repair guys in the business.