New to Four-Equidistant Strings, tuning questions

Hi, just joined the group as I am building my first Mountain Dulcimer, and have decided to set it up and learn to play four-string equidistant.I cut and bent sides, and am carving the scroll right now, so should be finished hopefully by Summer. Had to get the tuners before I started making the scroll, so I found four very cool NOS Grover 115 nickel banjo friction tuners for her, still in the box. It is going to have a short vsl, around 20" or so, and have a zero fret, 14 diatonic frets, and a 6 1/2 fret.So I read through the threads, and as I've never played a MD before, I still had a couple of questions:1) On a four-string equidistant, does anybody ever play the melody string and let the other three strings drone?2) What would be a good tuning to do Suite Judy Blue Eyes, Carry On or 4 and 20 by Crosby,Stills,Nash and Young? From what I understand Steven Stills used EEEEBE on the guitar. Also how to tune the dulcimer to itself would be helpful.I need to get an idea of what tuning I want to start with so I know what size of strings to get.Regards, David Messenger in Manitoba