Need Thai Phone Number With Voice Mail

[0x22b]

I've got several friends in Thailand that would like to contact me but who don't use email with any regularity. I'd like for them to be able to call to a Thai number and leave a voice message for me, or send me a text message. I need to be able to retrieve the voice or text message online from wherever I may be in the world. I spend very little time actually in Thailand. I don't really want a roaming service but maybe will be forced to do that if it's the only option. I think something like Skype In would be great, but they don't offer numbers in Thailand currently and I don't want my friends to have to call an international number. I'd also like the service to have caller ID if possible. Any suggestions? If roaming service is the only option, is that available with a prepaid SIM? Probably not and I don't know if I'd qualify for postpaid service because I'm not based in Thailand.