Buying in Beeville, you may qualify for USDA which requires a 580 score I believe.
FHA requires a 620. http://dallasloanguy.com/docs/about_credit.pdf
Here is a link to a free book about credit. Read it!!
Then you need to get with a loan officer who understand credit scoring real well.... you may be able to tweak a couple of things really fast and get those scores up!!
The minimum required in this market is 620 for an FHA with 3.5% down. You will also need a 2 year work history ,an acceptable debt to income ratio and sufficient income to meet the monthly note plus taxes & insurance.