Hello Graham!

Have you given thought to a plain shirt of a color complimentry to your kilt combined with a waistcoat and tie? The combination should be cool enough for the weather and still look sharp. I find that the trick for me wearing a tie in warm weather (somthing I must do for my job) is to be sure that the collar is loose enough that your neck can breath but not so loose that you have a huge gap.

Wish I lived closer to Denver it would be great to make your aquaintance in person hope you have a great time and many blessings!

Bill