I was so hoping the Ragley Troof I had was going to be my equivalent of what I think your after... but unfortunatley the frame cracked after less than six months (before I had even bought the 135x12 dropouts... luckily!).
I'm still looking for the same - I want it to take all the parts from my Nicolai; dropouts to take 135x12, full 1.5" headtube, 31.6 seatpost, ISCG... and be singlespeedable... and light.
I'm currently running a little Mmmbop as my hardtail and it does some of these pretty well. Although I would change it tomorrow if I find something else.
To run the 135x12 wheels in it I usualy change the (Hope) end caps but I also have an axle like this 135mm Axle at CRC. It's handy for trueing wheels as it's a straight shove in quickly and go ride/fix. Mine is made by Nukeproof from parts of the Forth Rail Bridge so I tend not to take it out on the trail.
The only way I can see to tick all the boxes is custom; Chinese Ti, Nicolai Argon AM, BTR Ranger etc... but as it's my second bike I'm not that bothered (until I break the Mmmbop ).