If you run E6--you'll probably need an electronic panel. The Wing Lynch panels are great--but you may want to check out a Hass Intellifaucet. For one thing, they're cheaper new--a basic model runs about $500. More importantly--the WL won't handle as wide a variation in water pressure as an Intellifaucet will.
If you look at manual panels--check out the flow rates needed for the unit to be accurate. Also--plan to have your plumber install hot & cold water filters PRIOR to the panel, and if you're fussy, after the panel as well. You usually set them up with check valves & vaccuum breakers as well as couplings so you can get the panel out for maintenance. I'd recommend a 5 micron filter--this may seem like overkill, but don;t go any larger than 25 micron. we use 25 micron on our paper processor water panel--and 5 micron on the film processor(s).
otoh--I thought some of those Jobos would temper the wash water internally & could be set up without external water hookups? It may be worth asking Jobo about what it takes to set up an ATL for location processing--you might be able to forego the expense of the water-panel if this is the case.
Sorry I can't be of much more help on this--but I do use a Hass Intellifaucet with a Wing-Lynch....and use 3 other manual water panels, including the Leedal you mention.
BTW--plan on rebuilding a water panel from time to time. If you use them enough, you'll probably have to do it about once a year.
my opinions only/not my employers.