30" inseam is going to be your problem. Thats My inseam and I am 5'6" short. I ride a variety of sizes- but you will have to look at the convention of Mountain bikers using smaller frames and longer seat posts.

Do not go by Frame size to your height- Sort the toptube as being comfortable and fit a longer seat tube.

Ok- I am extreme but I ride a 15" as my main MTB. I also ride a 51 on road bikes But On mountain bikes I also ride a 17" and a 19" Different manufacturers with different Geometry. And don't go for the same ride position on an MTB as a road bike. Road bikes do have a lower more stretched out riding position. Attachment is of my MTB set up for offroad. For road use I fit slicks and Flip the stem to give me a lower bar position.