Also, if you check out venishmartem (the Guard Your Eyes ads that appear on the top of half the pages on this website), they have a number for a frum family that sells meshumar phones for verizon.
Yes, the problem with getting it directly from the provider is that it is not difficult to renable it if you want to (assuming the phone is capable). Unfortunately I know someone who was receiving charges for a phantom line on their account and it was done through a frum store. Be careful. Also the rates are not as good as what you can get in Israel.
disable sms and internet on the account. as for the account password, do the same thing you would with the password to internet access on your computer so if you have the yetser hara to enable these functions, you wont have password to do so. of course, there are ways around this, but if you want to account for every possibility, the best option is, dont buy a cell phone.