A way to get around the ekit/MTS SMS text message block would be to send an email to
10digitphonenumber@text.mtsmobility.com from the handset. Have sent MMS messages to email addresses from my ekit sim so this should work (at least in theory...).
Another way would be to send a text message from the MTS webpage from a browser enabled phone:
Send a Text Message - MTS Mobility
Of the two methods, a flat text email would likely be cheaper because the web browsing function of ekit has to be in the UK number mode rather than the US/Canada number mode.
Phones/Wireless Devices: Doogee S90, Isatphone Pro, Amazon Kindle 3G, SkyRoam MiFi device, Karma MiFi device, AT&T Liberate MiFi device
Sim Cards: T-Mobile (Mint), AT&T (Mifi device or Kindle), Koko
Satphone: InMarSat
Broadband US Wireless Data: AT&T postpaid, Sprint (Karma Mobility prepaid)
Broadband International Data: SkyRoam
VOIP: Skype