I like the looks of this one -
http://www.amazon.com/Exact-Microsoft-Surface-BUCKLER-Series/dp/B00KGLC5F6 - I've had similar cases for other tablets I've owned and I really like the leather "clips" that hold the tablet in the case. Plus, the back isn't locked in to a case -- you *could* use the stand I suppose but I'm not sure how well that would work BUT, the good news is you have access to the microSD slot. It's not available til July 20, though. And I've never had a case from Exact so it could be ... uhhh ... not so good
I *do* have an IVSO case for another of my tablets, though, so I'm also looking at these
http://www.amazon.com/IVSO-Microsoft-Surface-Lightweight-Case-will/dp/B00KSVSKJ4
http://www.amazon.com/IVSO-Microsoft-Surface-Slim-fit-Multi-Angle/dp/B00KAOJBM4
You snap your SP3 in to the first one so the back is completely covered. The 2nd one is more like the Buckler - the SP3's kickstand is exposed so, if nothing else, you can get to your microSD slot.. Both are available now but not
Amazon Prime. Not sure if either has room or will accommodate a Type cover, either.