You certainly can sell them separately, the prices are down on them now though! I do have a client looking for a whole duplex, this could possibly work for them! Call me if you'd like to talk about it!
First, if the house isn't too old (maybe less than 30 years old), it's possible that a local real estate company might have the plans. The company I work for has multiple file cabinets full of the original developer folders/sales literature for thousands of houses/communities in the area. I wouldn't be surprised if there are real estate firms in your area that have the same collections.
If work was done on the house that required permits, it's possible that there would be architect's drawings of at least the area worked on at your city/county office that handles permits and inspections.
Another way--if it's in a community with similar houses--is to ask others in the community if they have the developer's sales literature. Lots of people keep that.
I'm sorry to be so late to this answer, but yes you can get a home loan with poor credit. You just need to use a lender that does manual underwriting. They will look at you the person, instead of your credit score. They take time at current residence, job history and time at current job, and your rent payment history. If you have been at the same address more than 2 years and have paid your rent on time, plus have at least two years in your current field and a solid work history then you will be able to get a home loan. I know several lenders that work with manual underwriting. If you still need help let me know. Again, I'm sorry to be so late to the party here.
Realty Executives of Kansas City
Leawood, KS 66211