Most tux shirts are made for bow ties, so you'd have to bend a bit there as far as shirts go.

IMHO, a PC doesn't look right unless one is wearing a bowtie. The vest isn't wide enough in front to accomodate much anything else.

I'd also ditch the fly plaid, but I also don't like them at all outside of a parade.

As far as hosed go, if you can get a pair of argyle ones (and/or don't mind the expense) to match your kilt, that'd be the bee's knees, as it were.