No recommendations from me, those three were on my shortlist then I bought a Planet X Sportive, but my criteria was a bit different to yours, for touring I'll still use my Hewitt. Some observations picked up in my search, some of which you'll have already gathered:
Fatbirds in Hunstanton seem to be offering the best deals, frame with fork & headset; September £809 or Yukon £856. They're probable the only place to test them side by side. I found them very helpful on the phone and when I met them at Mildenhall Rally last year. They were happy to have bikes set up for me to ride by appointment, though I didn't do so.
The brushed finish has some long term advantages, you can buff any scratches out with fine wire wool. If you mark a bead blasted frame there's not a lot you can do other than have it refinished.
The September seems to have better clearances then the Yukon, a friends Yukon takes 25mm tyres and I've seen a September with 28mm. I say seems because it could be the differences in manufacturers sizes, or the owners idea of what's acceptable. If I’d been looking for an only bike it would have been important enough to me to check it out.
The Enigma is a different beast, at a different price point, to compare like with like it'd be a custom frame from Sabbath or VN. The Etape uses double butted tubing unlike the plain gauge of the other two, I've no idea how much difference that makes, it's downplayed by the others, though they still use DB on their higher range bikes. The Etape also uses standard reach brakes, which will restrict tyre choice with mudguards. Having said that, they really will build what you want, a friend has an Omega with plenty of clearance for 30mm tyres plus a few other different touches and there are photos on YACF of one with disk brakes. If you got on well with Paul Hewitt, he can get Enigmas made to specification and I think he stocks VN.
Enjoy your looking, you'll get a great bike whichever you choose. I'd be weary of leaving it too long, the prices went up 20% while I dithered and several people have said there's another price hike due in the near future.