In general I really like the idea of a Kitchener helmet with a kilt -- a vintage military look that's certainly appropriate to a hot climate. However I worry that it might come off as a bit "costumey" -- not that a piper in full No. 1 dress isn't a bit over the top in most civilian circumstances anyway. If you're trying to recreat the Victorian look, great -- but I'd suggest doing the research to make sure you get the look absolutely correct:















There are a number of vintage militaria sites -- such as What Price Glory, The Quartermaster, Mess Dress, IMA, Replicaters, etc. -- where you might be able to pick up the appropriate odds and ends.

You might also check out this thread.

I think the Black Rock Ranger gig is another matter entirely. From what I know -- only vicariously -- of Burning Man, the sky's pretty much the limit on your creativity.

I Googled up some pictures of kilted BRRs, and most seem to go for a less formal look than what I envision from your description:





Personally, I'd opt for what's most practical for the desert heat -- but if you want to go with the Kitchener, spats, walking-stick/parasol, etc., that's certainly your call.