Not really sure what you are asking for. I think all clincher rims can be used tubeless. Not just those who claim they are tubeless. Remember this fact. DT and Velocity make several rims that are very suitable for touring use. 36 hole. Heavy duty. There are probably other rim makers too. Shimano makes a variety of road and mountain hubs with 36 holes. Wheels are fairly easy to build yourself if you are inclined. And you can hire a local person to build them for not much money. Or online places offer this service too. Spokes are $0.50 to $1.00 each for DT and Sapim double butted 14/15. So its very easy to build exactly the touring wheel you want without much fuss at all. What is the problem?
What you are asking is reminiscent of the olden days when all cranksets in the mountain/touring world used 110mm bcd and 74mm bcd centers. Road used 130 and 135mm. Back then there was no point complaining that your crank did not have the right chainrings that you wanted. You could very easily buy any chainring size on earth from Campagnolo, Shimano, TA, Stronglight, Sugino, etc. Put them on your bike and you will have exactly what you want.
Just buy the wheel parts you want and assemble them yourself or hire someone. Then you will have exactly the wheelset you want. Its really not that expensive either.