[driverdan]

Better Voice[1] is pretty close and reasonably priced. They use Twilio so I'm sure they'll add MMS support soon. Disclaimer: I know the founders.

1: https://www.bettervoice.com/

[aroch]

Looks a little more involved than I need -- I already have SIP trunking through someone else, I mostly just need the SMS/MMS side of life