Congratulations on your decision to purchase a home! You are going to be one of the few in this nation that gets to tell a great story in the future about how you were given $8,000 to purchase a home with less than a 5% interest rate. It''s going to b e one of those stories in the future history books and you are lucky enough to qualify, so congrats, and I hope you are excited about that opportunity.
Home prices will not be skyrocketing up, but interest rates are another story. You simply do not know what they will do, so the faster you are able to complete your purchase, the safer you are in locking in such a low interest rate. Do not fear so much "buying the wrong home", rather "missing out on such a low interest rate".
I say that because when the rates climb, they climb fast, and it will change the game entirely, then you may find yourself rushing to buy a home, and that's how you get caught up in the wrong deal. So, if you find a home you like for multiple reasons, STRIKE... while the iron is hot!
Now, First thing's first....
Have you hired a great Realtor? And, I don't mean a great friend who is a Realtor , and I don't mean a Realtor that promises to give you money if you do business with them, or even a Realtor that simply has a bunch of "years of experience" stacked up. This is a new world order out there, so find out what makes your Realtor so great, and understand how that will play into "YOU" having a successful First Time Home Buying experience.
Whatever you do, do not start this alone. Do not rely on Trulia to carry you through successfully. It will cost you greatly in misunderstood, indirect advice when it comes to the real home, real location, real neighborhood, the real condition, and the real deal.
After hiring a truly great real estate Agent (Realtor), then go through a discovery phase with that Agent so all your answers can be clearly defined. This is highly effective and much needed for your success.
As far as "Duplex or House" goes, it sounds like you have an itch for an investment, in addition to a place to call home. Could be a good thing, or it could be your first nightmare. Some additional questions that you would never think to ask yourself, need to be answered to better uncover the direction that will satisfy you the most...
There is so much to say about both Houses and Duplexes that will greatly effect your decision.
One little secret for you to walk away with here is, if you desire to live and rent a Duplex, try to find one that is not in a "Duplex Haven" or "Duplex Row". Find a Duplex that was a "one-off" build in a neighborhood full of homes. This will lend you more "pride of ownership" and neighborhood enjoyment, plus it tends to lend more on the resale factor. Certainly do not count on finding many of those available, however, just know that they are higher demand in the Duplex world.
To gage your vision level; how long have you lived in Austin and how familiar are you with "pocket" areas?