I second the English suggestion.
Thorn bikes are great, and a
really fine value--especially the Raven. Thorn himself seems like a hoot to deal with too. Bob Jackson deserves a hearty mention as well; great value for the money. My uncle has an old Hetchins and a 1970s Mercian that are both to die for. I'm being turned into a Mercian freak, personally, and this is the bike I've chosen for my dream tourer, which is being made now.
For £375 + S&H (King of Mercia stock frame), I'm not sure how you can beat them, actually. Although extras on these frames
can quickly advance the cost if you go overboard. It will still end up costing considerably less than other top custom tourers. They make superior-quality English steel bicycles with great cast lugs. The staff are easy to work with, they've been hearth brazing the same way for 58 years, and they will build the bike to any specification you desire--including 26" wheels--for several hundred less than a Waterford or an Atlantis (the latter, although unquestionably amazing frames with really well-thought-out geometry, are not particularly custom at all and are still $500 more than a Mercian KoM).
They are one of the last bastions of old-world English building, and it's a good time to cash in on that, especially if you're a Reynolds 531 fan, as they have a fair bit of it left at no extra charge. Witcomb and Longstaff are two more frame builders that seem really good in this respect. Mercians also look just plain classic, although I think the color finishes they chose for examples on their website are not all so hot.
http://www.merciancycles.co.uk/
A small
gallery. My bike will look a lot like Craig Montgomery's in that gallery, when all is said and done (but with far more relaxed angles), only I'm passing on my savings on the custom to invest in a Rohloff for the bike.
...and here's a
quick look at some of the variety of pretty finishes you can get (that choice is entirely up to you). I especially like that one on the top right--my uncle's is similar--but it would probably get stolen quickly unless you shelved it in a Brinks truck or live nowhere near a city. I went with a much more humble look to mine.
Good luck, whatever you choose!
EDIT: I remember velonomad recommending Tom Teesdale once too, and I generally have liked velonomad's ideas about this stuff. You might want to check into his frames.