Lol... If you find one, lemme know. I'm a text-aholic, so I'm sending ~6000 a month, and I like to archive my old ones (OCD I guess). The only solution I've found is to use TitBackup and every month or so backup all messages, then put take that backup and put it on my computer, and delete all messages on the phone.
Xperia ion - Retired
Galaxy S4 - Backup phone (slightly cracked screen)
Xperia Z2 - Current phone
Xoom 4G - Retired