vista upgrade to 7

hello to all i just wanted to know about windows 7 upgrade u see i am thinking about upgrading to 7 but the thing is i dont have a coa yet but i am going to purchase one through ebay but u see the thing is this coa is for 7 home premium now when upgrading i have one of those upgrade anytime cd's now when i install this cd will it let me choose what version of windows 7 i want to install or will it choose home basic 7 because my system is running home basic vista, and furthermore will this coa work for any version of 7 or does it have to be strictly home premium 7.
THANKS IN ADVANCE
RUBEN