I have all of the guns that have been talked about here and everyone is right. The M&P 9 range kit s a killer deal and won't hold you back a moment if you practice enough (a bit of a stupid statement as practice will make you better with any gun). The CZ is a fantastic gun and lots of my fellow three gun shooters admit that it represents performance at a great price. All of this being said striker fired guns are very simple to use and won't hold you back one moment or point. Tight budget? M&P 9. Fatter wallet? CZ. Bit of money to burn? STI.
Your pistol is only 33% of the game remember. Personally I think that the shotgun is the most important gun to get right and your AR choice is second. Your pistol is the least expensive firearm to practice with so your choice is less critical.
Enjoy your guns, don't get gear crazy, instead shoot alot. You'll be just fine. It's a fun game.
