I like the Fabco, both the NV-55 and the NV-55-18 which is the same valve except the -18 is larger to allow using the 1/8 inch solid pipe rather than the much smaller -55 which uses a tiny 10-32 fitting. So which I use depends on how I am running the CO2. At times, having the whole thing mounted at the CO2 tank seems right but other times, I like having as much OFF the tank means I am less prone to breaking the small stuff when changing out tanks for refill. This matters more on larger tanks as the CO2 tank is more awkward. I use Grigg's reactors on large tank and that means very low pressure like 4-6 PSI which is ideal fo using the NV-55 as a smaller, cheaper options that I locate on tubing out and away, usually mounted somewhere on the stand where I can see and adjust it easier than on the CO2 tank itself. If you use the Dwyer, it seems really easy for me to run both inline on tubing. That lets me set the needle valve right beside the meter that I'm watching when adjusting.
For the question of the sizing of the Dwyer, I might throw in some thoughts on the sizing if it would help. It probably has a gauge labeled on the front that tells max-min readings? What do you have and we can go to some online converters to do a rough guess about how it may work.