The only thing that really makes a "kilt jacket" a kilt jacket is that it has a high waist, so that it fits better with the kilt. That's really it. All the other stuff you commonly see (gauntlet cuffs, diamond shaped silver buttons, eppauletts, etc) are a nice extra touch, mostly inherited from the military, but are not necessary in the least.

Take an average Prince Charlie jacket, remove the gauntlett cuffs and silver buttons, and what you have is a fairly standard tuxedo jacket like the one you see here. This would work perfectly well with the kilt. You'll like very sharp, and save yourself a few hundred dollars to boot!

Aye,
Matt