Question for you all...I am in the market to regrip the following clubs:

909D2 - 45 inch VooDoo stiff shaft - .630 Butt Dia.

AP2 710 - Dynamic Gold S300 shaft - .600 Butt Dia.

I currently have the stock grips on all these clubs.  My questions:

Is it appropriate to regrip these clubs with a grip that has a .580 dia?  If I do this will the dia. of the butt of the club remain .630/.600 or does it decrease because im using a smaller grip?  I need a little bit larger grip than what is on there currently.  Does this mean I would need a midsize .600 dia. grip...what about a midsize .580 dia. grip? 

Will a .580 dia grip even fit on the driver?  If not, what dia. grip should I purchase to fit on the driver?

Thanks for the help!