I like the great kilt/formal attire look, but I have to agree that the PC is the wrong jacket. A short waisted doublet is the best choice, I think. Either a regulation doublet with white tie or a Montrose style doublet works well, and I've used the Montrose with a jabot to good effect. (At least I thought so. ) Your outfit doesn't look bad at all, but it doesn't really look formal either.

Getting the hang in the back is a little tricky, and I have to disagree with Chaz on this: it doesn't make you look fat; it makes you look like you're wearing a great kilt. I have found that if I pull the opposite corners of the left over part toward the rear before twisting and pulling together over the left shoulder, it minimizes the excess material gathered around the waist which admittedly can look a bit odd by modern standards.

Also with a doublet, I prefer a pretty large waist plate/buckle to set off all that black. Sitting above your sporran with the silver cantle will make the outfit shine. With a Montrose, there are little hooks on the outside of the jacket in which the belt sits to keep it just at the bottom of the doublet so it looks very smart sitting over all that tartan.

You rarely see a great kilt worn these days except by reinactors and others of that ilk, but I like the look and have seen it worn to great effect when time and planning go into donning and wearing it. It does take practice.