As the other's have answered below, there are a few options to purchase a house here in Sonora.
1. you can take a line of credit out against the home that you have in TX.
2. you can do what's called a "cash out refi" on your home in TX.
3. you can just purchase a home here in Sonora with approximately 20% down. Your payments on a loan of $200,000 at todays interest rate, including taxes and insurance would be approximately $1250.00 a month.
The first two options would allow you to "pay cash" for your new purchase. This would allow you to own the home here in Sonora outright however, the new loan would encumber your residence in TX. The third option would just be a loan on the new purchase.
As for rentals: In general a 3 bed 2 bath 2 car garage home on a town lot will typically rent for $1200-$1400 a month. I can help you with exact numbers when the time comes at Mark@MrHomeGuru.com
If you would like to search the homes currently for sale in the Sonora area here is a link: http://mlssearch.topproduceridx.com/MarkPradenas
I look forward to answering anymore questions that you may have.