Depending on your price bracket I'd look at
Decathlon/Edinburgh Cycles as the cheaper end of the scale, Surly LHT or Ridgeback Panorama at the upper mid point or I'd go custom if I was spending more. Treat it like a checklist, so make a note of:-
what you want to spend
preferences on frame materials
preferences on types of handlebar
what frame fittings it should have
disc brakes or not
how much clearance you want for tyres
and any other details that matter to you, then see what OTP options come closest
I have had a Surly Crosscheck followed by a Salsa Vaya both of which fall into that sort of 'adventure' category that seems to be getting used instead of tourer at times now. 700c wheels, clearance for up to about a 700x44 tyre, mudguard and rack fittings and geometry somewhere between road and touring. The Xcheck was a great frame but didn't take disc brakes and so I moved to the Vaya, which I've since replaced with a custom Ti frame, but again with discs. I kept the big clearance ability though and initially had setup with drop bars and STI shifters, I've since moved to an alternate style flat bar. I also have a Ti 29er frame, from the same builder, and again with rack and guard mounts, just awaiting the Rohloff to complete the build.
If you're not set on drop bars then there are quite a few other options around now, Europe and Germany in particular tend to have a bigger range in this respect. Thorn now offer the Mercury which falls into the same sort of category as well, available with flat or drop bars. If you went custom it's perfectly possible to size the top tube so that you could run drop or flat bars. Particularly if you use bar ends with the flat bars or any of the alternate flat bars that extend forward of the clamp area like the hoods position of drop bars does. Getting a fit for drop bars based around a 90mm stem would allow you to easily add 30-40mm via a longer stem if need be.
It depends on what sort of riding you want to prioritise and how versatile you want the bike to be. Both of my bikes have the same Mavic TN719 29er disc rims, which are rated from 700x25 up to 700x60 tyres, personally I don't have smaller than 700x32. The roadier bike would be good for commuting, lightish touring on roads and stripped down for faster weekend rides. The 29er has a temporary wheelset on at present and has the rigid On-One carbon forks, I've ridden it with 700x56 knobblies and 700x40 slicks. I have to say it's pretty darn nippy with the 700x40s on it, its intended use is for offroad or mixed surface but it's nice to know it can do other duties as well. It would make a great tourer if you wanted to do serious 'any surface' type touring, like one of these across America offroad things. The 29er could also be setup with suspension forks if I ever feel the need.
I know things keep changing but my general impression has been:-
classical tourer - canti brakes, clearance up to about 700x32, drop bars, fully rigid
adventure tourer - a mix of canti/v/disc brakes, clearances up to about 700x44, drop or flat bars, fully rigid
offroad tourer - disc brakes, clearances up to about a 2.2" tyre, generally flat/sweep bars, front suspension an option at least, 29ers becoming more prevalent than 26"
