After having a few issues with Workswell, but wanting a similar frame, I finally settled on the Dashinebike 29er on AliExpress:
http://www.aliexpress.com/item/2016-new-style-China-29er-MTB-Bike-29er-Carbon-Frame-135-10-and-142-12mm-thru/32546313850.htmlInitial impressions are good. Quality looks on a par with the workswell. It came with a Headset, seatclamp, and both QR and TA dropouts (and the sent me some spare qr dropouts too).
It was fairly easy to deal with them, and they were very patient, since I was asking a lot of questions, to make sure that I was getting the exact spec that I needed.
Weighed in at 1Kg on my work scales, I probably wouldn't want to go any lighter on a chinese frame.
Some other pics