I haven't been there yet, but you might look for clubs at 2nd Swing. I'd encourage you to get used clubs. But before that, I might recommend that you call Golftec and sign up for a lesson package, and ask them what single club you need -- its either a 5 iron or 7 iron. Maybe they have a loaner you can use. Then, they can do a club fitting for you and they also sell clubs that would be custom fitted. At the least, you have a better idea what you need.
If for whatever reason you can't go to Golftec, I'd recommend you find a set of clubs used fairly cheaply. I don't think it would make much sense to buy a new set of clubs only to find out in 3 months or a year that you don't like them or want something different as your game progresses.
I play with Mizuno MP-33 blade irons. I'm not a scratch golfer, in fact, not really even close to that. However, I've played with blades since I started and I think thats the best way to learn the game. The so-called game improvement clubs don't "improve" your game. They may just mask swing flaws. That's fine for people who say, "I just want to play with the swing I have and deal with it." If that's your attitude, then get a set of Callaways and go for it.
Also keep in mind that 3-9 irons aren't necessarily the most important clubs in your bag. Wedges are very important and you may want different brand wedges (including sand and lob, if you want to carry those) from your irons. I use Titleist Wedges. In addition, fairway woods are important and I'd recommend you learn to use those as proficiently as possible before moving onto a driver. I know guys want to get a hot driver and rip it, but if you have a wicked slice that sends it into a lake, the driver won't do you any good. 225 yards on a drive, fairly straight, from a 3 woood would do much better and you'll get under 100 much faster (trust me on this -- I've put a fortune in balls in the water).
Before I went to Golftec (Bogart Golf is another, similar place -- both do video analysis), I took lessons from the Nike school. They have those (or did -- check the web) at various courses around DFW. I had a good teacher, but since it was a class, there were a lot of things he talked about that I didn't really pick up until later -- didn't understand them on the first time. Examples: spine angle, slot, etc. Regardless of where you start, you can not beat video lessons. What you THINK you are doing and what you are actually doing, especially when you start, are two VERY different things. If you see yourself on video, you likely will grasp things faster.
One thing you can do now, and without clubs, is stretch. Flexibility, including upper body, may make the difference in how fast you improve.
Good luck and have fun.