For the last three years we were ordering zooplus out of Germany for delivery to Sweden (where the cats were living) and they had Orijen stock (at least as of February when we made the last order). We did just put in a huge order for UK zooplus this week because they are moving back to us next weekend, but didn't get Orijen this time so not sure if its currently not available in this market? (update: looks like supply issues)
Re: wet food - ours are super picky and wont eat anything unless its gravy and practically a liquid so we are limited to pouches. They refuse anything beef related so like you I tend to stick to stuff with wings (evolutionary or not) - chicken, turkey, duck (oh man they love the duck), one or two things with fish (but not too much). It seriously cuts down on our options so we either feed raw if we are also making chicken for ourselves that night OR they get a pouch of "junk food" - Gourmet Perle they seem to like. I dont like feeding 100% dry because of the water issue, so at least it gets some liquid into them.
For this next order we are going to try them on:
1) Meowing Heads dry food - got a sample bag as it has good reviews (but does have some cereals/starch added)
2) James Wellbeloved pouches - so far they have turned up their noses at Cosma, Animonda Carny, Bozita, and Applaws wet food even though it was gravy-style loose in a can. WTF guys.
I also got one packet of Lillys Kitchen that is supposedly loose but it looks like they only do pate style so... its only 90p if they dont eat it.
Oh! Have you tried Purizon dry? Ours love that one as well and its 0% added grain. Could be a good substitute for Orijen? (also, its a smidge cheaper)
I can also recommend the freeze dried Cosma snackies - 100% chicken or fish. They like those as a treat.