You're shooting down good suggestions here, so I'm not sure if you don't fully understand the problem, or are asking for the moon.
Are you wanting to send SMS from a specific device and SIM, or just ANY kind of SMS?
SMS is controlled from your provider. If you want to send from said provider, you need a device or app that can access their network. T-Mobile has a browser-based interface for this, and I think Mint does as well. Otherwise you need to get an SMS provider with an API to interact with, like Twilio, VoIP.ms, or similar.