I need some advice. I have a hk uspc in a .40 and an hk usp in 9mm. Now i am going to get an hk p2000, however i can not decide to get it in a 9mm or .40. I have a uspc in a .40 and the mag's are interchangeable so i will have extra mag's from the get go. But i do like the 9mm round because it is cheaper to shoot. I can not decide and i know i do not want the .357 sig so what should i do 9mm or .40.