I've spent ages playing with gauges and decided that I like 11,14,18,28,38,49,68 best for Dstd (and Eb when the strings get knackered and I can't be arsed to change 'em :lol:) but that's on a 25.5" so pretty useless info for you. I reckon 11-52 will be good in Dstd for your Gibson with the action raised a bit but you might find it to floppy in C#. Why do you need two tunings on the same guitar?