Make sure you get one of those shirts with the brands all over it that makes you look like you are sponsored. I hear they make you shoot faster and add +3 points to your Look Cool Factor.
Also, you need more Mags.
And I would like to echo what one guy said already, get a holster that is specific to the gun. There is not a lot of variation in the critical dimensions of most pistols, so universal holsters are getting better, but given you plan to compete, there is no need to trade performance for the sake of saving a few bucks. Holsters are kind of like shoes. You will end up owning many of them depending on what kind of training/shooting you want to do. You can't go wrong with the bladetech, and even if you do upgrade you will probably never see the need to sell it.
I probably own an average of 2 holsters for every pistol I own, and the ones I shoot most its more like 3 or 4. Holsters may seem expensive, but if you seriously dive into this sport, it will be nothing compared to what you will spend on ammo.
Lastly, buy ones cry once is something you need to live by. Every time I have gone cheap, I have ended up upgrading anyways, and in the long run you spend more money and only suffer through the cheap stuff.