I would use Shining Armor's head with a female body and bulk out the chest. Shining Armor's body is not really suited for a suit (see what I did there? LOL). I already have dastardly plans for Cadence and Shining Armor when they come out. BWAHAHAHAHA!!!!
I had that Luna sitting around since I bought that set to make Chrysalis and I'm finally doing something with it, but I had originally planed on making season 1 Luna with it. The body shape left me annoyed though and I didn't feel like elongating the legs, thinning out the torso, etc. was a good use of time considering that August isn't too far off.
Warning: the glitter on that damn Luna is a pain in the ass to get off. I hate glitter so much...SO MUCH!!!!!
At the place it always has been from the very first moment of manufacturing: [link] Notice that the tail in G4 ponies is put right where the "IT" should be - see number 35 at this. Most customs don't change it because they hardly notice it - including myself. When my sister pointed this out, it was so much of a shock I cannot unsee it anymore... Had to stop my Fluttershy for a while.