I totally like that cap matching the kilt. I might have to try and find one when my ancient Grant Hunting kilt arrives. A what's this deal about no tartan above the waist? I think ties and plaids look good. The great kilts (not even going to try the gaelic spelling) had tartan above the waist.

I think a tartan tam or Balmoral would work with a matching kilt. I agree with Bob C. regarding the Glengarry though, best left to bands and those in the military.