ORIGINAL: i3dm
Oli, you can always use the non pro unit (no display), install it anywhere you want, and then use a pressure gauge on your tray.
Yes, that's what I have on the F-18F. But then It is nearly as practcial to have a separate system.
Also, having separate valves, you can separate the tank source ( ie have as many tanks as valves ). This can be very important for high flow demand setup like the big FEJ F-16.