Yes there is another option!!! Read:
I had similar frustrations with the linking bundle being out-of-stock so I purchased a Raspberry PI from Amazon, ordered the URIxB interface direct from the manufacturer, made a DB25 cable (according to the pin outs of my repeater), installed the PI image from myGMRS and requested a node number and password (also from myGMRS) and I am now successfully linked to the network. There is ZERO support for this option but there IS plenty of documentation out there to help. It's a split image of Allstarlink's network just tweaked and used for myGMRS. I literally just finished my setup and now I am configuring it all to my likings. I will be going live in a few days.
Hope this helps....
DesertRover (WRCS363)