I am going on an eight day tour of the islands, and after that I'll be living on San Cristobal where I'll be working for a month. I would like to have cell phone service in the event that there's an emergency in the states for which a family member needs to contact me and vice versa. I'd also like to have it for the convenience of travel related glitches, otherwise I don't plan on using it too much. Any advice on the best and most cost effective route to take? Thank you!