I can't recommend someone as such, but someone who maybe could, is the reseller/distributor that you purchased the unit from.
They will have other customers who purchase the same UTM devices, and should know which customers who offer this service and who to recommend that can complete the tasks you are after.
Hope this helps.
Hi, maybe i can help you out... just for exercise my english ;-))
Just open your BOX for the outside and we will do this via phone.. (i live in germany)
a vpn should be no problem,
but we have to work a little bit on the voip connection getting out on a second line through the GW...
maybe you make it workable via policy routing?
I was able to figure out the configuration myself.