Thank you all for your updates. I've started talking to Libelium about getting one of their Meshlium LoRaWan Gateways.
http://www.libelium.com/downloads/documentation/meshlium_datasheet.pdf
If I can't make any constructive progress I'll be reverting to the Multitech device. I've also now got direct contacts for the Kerlink equipment and the RFI L Gateway. I'll compile a table with all the contact details later and put it up on here (or somewhere).
Again thanks all for your replies.