Duane,
Here is a pic of the gauge I am going to use. Picked it up at a local trike shop... same gauge they use when adding a trike kit to a bike. I know..... the gauge doesn't match the other gauges. Black or white was the best I could do. If anyone finds a matching gauge, I'll be in line to get one.
One minor problem with the gauge: The gauge came with a 3mm (or 1/8"-not sure) hose connection. The Arnott system uses 4mm hose. I couldn't find a 4mm fitting for the back of the gauge, so I called Arnott. I also needed an additional T to make the connection for the gauge (apparently the compressor for an 08 SEUC is a little different due to the ABS). They sent me a fitting for the back of the gauge, 6' of
1/4 inch hose, an additional T and the fittings needed to make the connections down at the compressor. And to my surprise, all at no charge for parts or shipping. The folks at Arnott are great to work with

Can't give any advise on the shock adjustment yet. I put the gauge in the fairing a week or so back when I did the handlebar change. Will hopefully finish the shock install next weekend.