Thanks for the reply. I do ultimately plan to have a board built with what I need on it and had come across the Nimbelink stuff in my research. I could probably get away with at 3G modem but, then I need 2 different versions, one for Verizon and one for GSM. I'd ideally like to have an LTE version that could use either carrier but, I don't think it's going to be practical since some of the areas I'll have devices in will not have 4G/LTE service available anyway, so a 3G is probably a better option for now.
Right now, we're using the Raspberry I/O board for a proof of concept and to nail down exactly what interface ports we'll need on a designed board and I'm thinking of trying one of these with it - https://www.digikey.com/product-detail/ ... ND/6612636
. What isn't clear to me though, is if this is just a case and I need to add the modem module to it or if it's part of the kit, I've seen some conflicting documentation. Gumstix offers the Nimbelink as an option on their board design service so I'm leaning towards it right now.