Since I want to eventually upgrade to a 48v system any monitoring or meters I buy should be able to be used after the upgrade I don't want to buy something 2 or 3 times
Frank, I would hesitate to buy too many things if you plan on upgrading your system. All that you want is integral in most high-end off-grid power systems. We have complete system monitoring and controls on our kitchen wall that tells us everything we need to know about everything - and it's all integrated with the system and comes with it without using a bunch of hacked together meters:
We have a TriMetric there and the only reason we have it is because it has large easy to read numbers that can be seen from clear across the kitchen and we can see at a glance that our batteries are at 77% SOC tonight.
We also have a much more sophisticated Battery Monitor in the power room:
The Conext monitor is considerably more expensive than the TriMetric but it integrates with the XW and SW power systems over Xanbus. It keeps track of the number of lifetime cycles on your batteries, the lifetime average depth of discharge of your battery bank, tracks two midpoints on your battery bank to tell you if your bank is balanced or not, and even tells the AGS to start or stop the generator based on battery SOC. And it logs all your battery bank's operating parameters, including for the midpoints, once a minute for over 10 years.
My wife and I have been where you are right now and I pieced things together. When we first built here it was new and exciting and I had a blast designing new things, trying new things, and coming up with ways to make it work better. It took us 7 or 8 years, it started getting old and too much maintenance and too much work, and we decided we're going to be off-grid for the long term. We decided that it has to be easier and more automatic because we don't want to baby sit it all the time - we had gone NO PLACE in 7 or 8 years because we had built a system that had to be constantly attended to. NOTHING we bought for our original system was able to be used when we finally decided that we had to do something different if we're going to be in this for the long term.