That's a pretty versatile jacket design. I especially like the way it looks in lapelled configuration... I may be getting one to go along with the GK. I didn't initially see that the facings were buttoned back in the photo with the blue GK (I had mistaken them for decorative facings, as I am not horribly well-versed in such things). I quite like the idea of a double-breasted kilt jacket with a number of possible configurations, especially with the option to have a stand collar and closed front to guard against the frigid Michigan winter. As you can probably tell by my interest in modern great kilting, I too like some historical flair in my attire, Highland or Saxon (I'm also a massive history geek, so there's the core issue right there).

As for the pleating, It seems that the standard knife pleat config turns out looking a little neater, and as you have mentioned the "box" pleats are probably more difficult. As for yardage, it seems like the 4.5 yards doesn't yield too horribly many pleats, although I'd imagine that the six yards recommended for us larger gents (at least on The Celtic Croft) might cause issues with too much cloth on the top half.

Regardless, it would seem that the "modern great kilt" is certainly do-able, provided that one has the bearing for it and can wear it well. Some folks just seem to be born to wear it, other just end up being worn by it.