I'm using a moko shell case with clippable kickstand, it's a bit battered right now as I take my surface nearly everywhere with me, but it actually clips onto the kickstand.
Of course, this reduces the largest angle you can have the surface down at, but I've found this is perfect for drawing.
There are a couple issues however, the surface has a tendency to slide down when you angle the stand, but when you're not using it, it slides back up into place, and this also actually pushes out the little flaps that are used to secure the center of the kickstand, so I've had to remove the glue from them...
functionally, this does not really affect the device at all, but I did not know that this case would damage my surface pro 3. I mean, again, it does nothing to the surface itself, and protection wise, the case is actually very solid.
Personally, I would probably end up using this case for the rest of the device's life if it doesn't give way first, but I wouldn't recommend it solely for the reason that it damages the device after a while. I mean, it's negligible to me, since it's not going to do any further damage and it doesn't affect the performance of the device at all, it gets the job done in terms of protection and functionality.
Here's an image of it:
http://i.imgur.com/a6K945s.jpg
This is what it did to my flaps (I've just completely pulled them out and removed the glue, since they prevent the stand from closing properly if they were left halfway in):
http://i.imgur.com/3ZEkgm4.jpg
Rest assured, the rest of the device is fine. I'm just here to warn about this case.