Help! Need an Italian SIM, special conditions...

I am looking for an italian mobile number that I can keep current and charged up, ideally both from Italy as well as the states. (I am in the U.S. now.)

I am about to print materials for my business, and want to include an Italian mobile number. (I have family in Italy, and may be moving there next year.)

There seems to be so much information out there, I don't know what's what: possibly I won't be able to update some SIM accounts from a US website, some may not have voicemail (those through roamsimple.com). And then there is the ability to keep the number active.

Generally, I wouldn't use the number when I'm here in the states, but it would be good to have it be active so I could check voicemail as needed. And it would be great to be able to give my number to business colleagues in Italy before I travel, and know that the number will work!

The best of all worlds would be where I could transfer the number to a billed account when the time comes.

Any ideas to my best options? I won't be traveling anytime soon, and I need to print materials relatively soon.

Does prepaid GSM still sell SIMS?

Thank you,
M