Allegedly, on or about 9 May 2019, Bob Goodwin sent:
Everything I have read says Viasat's equipment must be used. ... It also contains a voip adapter for the telephone, before this "system upgrade" two months ago that was separate.
If it's a standard VOIP thing, then you probably can continue to use separate VOIP adaptors. If your phone plugged directly into their all- in-one box, and/or requires special configuration by the service provider, then I'd say no.
I will attach a sketch of what I have to work with now. I did determine that their router/modem could be put into a bridged mode but I could not get an internet connection with it and after a visit from their "technician" it was decided I could not use that mode?
In bridged mode, the modem is purely a modem. The first thing it connects to on your system (e.g. your own router) is what the ISP sees as the first thing on the network. In that your case, your ISP might need to authenticate your router (normally they'd *allow* their own equipment). But some ISPs don't disallow customer equipment, anything you plug into the socket "just works." If you can plug a computer straight into their modem, and if that works, then plugging it into your router ought to work.
What I need most now is a good instruction for setting up the NAT stuff with my LAN ip changed to 192.168.0.xx which I think will make it easier for me to follow.
Your choice of LAN IPs (all on the same subnet) is probably why things didn't work, before.
It shouldn't require anything special to set up NAT. It's just going to be the same kind of thing as the first time you set up your LAN. Set up your router to use the subnet that you want to use, let it configure the equipment you haven't manually configured. Then on the rest of your gear that you need to manually configure, set them to use new IPs in your new subnet range. Your router would be already doing NAT all by itself, anyway.
Forgetting your internet service, for the time being. Just connect your LAN equipment to your router, and get that all talking to each other on your new IP subnet.