I would need to know a little bit more about your situation to completely answer this, but let's give it a shot anyway.
USDA - Your household income must meet certain guidelines and this type of loan may only be used for homes in eligble rural areas. You can enter you City, State and Zip Code at this website, http://eligibility.sc.egov.usda.gov/eligibility/welcomeAction.do
to determine if you are eligible.
Vendee - Vendee loan financing is available on VA-Owned Homes. Unlike VA Loans, you do not need to be a Veteran to obtain Vendee financing. Vendee loans have extremely low fees as well as low, or even no, downpayment requirements which is very attractive. The only challenge here is that you can only by a VA Home, which are much fewer in number than a traditionally financed home. You would need to meet with a Real Estate Agent familiar with VA Homes to gain entrance into these type of homes.
FHA - This seems like the best choice given what we know about your situation. FHA sets a limit on the purchase price of a home, based on your state and city... this gives you a much wider variety of homes to choose from then the USDA and Vendee homes... FHA only requires 3.5% down... so if you were buying a $100,000 home you would only need $3,500 for the downpayment (Guess I didn't need to explain that to a teacher;). In Georgia, it is pretty common to get the Seller to pay for your Closing Costs, but you would need to confirm if that is standard in your area.
Couple other things at play: 1) You must take advantage of the $8,000 First Time Home Buyer Tax Credit before 12/1/09. You need to allow at least 45 - 60 days to close once you have an accepted contract on your home. So that gives you a timetable. 2) In Georgia, the State also provides an additional $1,800 Tax Credit... not sure about Texas, but it is worth researching. 3) Rates are still low, but I would act sooner than later... they have climbed the last couple weeks. I would get pre-approved by a Lender and lock into a rate while you look.
What an amazing time to buy!!! Good luck and best wishes.