Arken EP-5/Savage 110 Tactical ring height

I'd start with medium, if you were to upgrade the stock to something with an adjustable cheek piece getting the scope as low as possible wouldn't matter as much. If your sticking with the factory stock I would imagine getting it as low as possible would probably make the gun more comfortable. You should be fine with factory rail, I would do the things you mentioned.

https://www.snipershide.com/shooting/threads/ring-height-info-how-to-measure-correctly.20706/





that might help you out.