Romantic-era bonnet ramblings

I still haven't figured out what kind of collar (if any) I want for the 1830s dress. I may run out of time and not make one at all. But I did start on the bonnet. I mocked it up with paper on Tuesday, kind of loosely basing it on the shape of my Regency tall bonnet, except with a slightly shorter crown and an absolutely ginormous brim. Naturally, I either did not make or just could not find the pattern I used for that, so I had to figure this out by basically wrapping various shapes of paper around the Regency one, then tweaking them and doing it again. I did get to the point yesterday, though, where the shapes appear to be working, so I cut out the buckram layers. I'm still kind of waffling about what fabric to use to cover it. I think I have enough of the plaid left where I could just do that, but I don't want it to be matchy-matchy. But I don't like any of the other silks I have except these deep burgundy/crimson, which would be perfect except that I currently have barely enough where I can maybe squeak out a garment, so I don't want to use up any of it on a bonnet. I have a similar color in a poly taffeta, but I feel like it's somewhat obviously poly. I'm debating about hitting Joanns on my way home tonight, but I know they're not going to have silk, so it would just be about finding a fabric that maybe doesn't look 100% poly... I don't know. I wish I had olive silk. That would be perfect. 

Here's a pic of one of the paper mockups. I changed the crown to be about .75" shorter than the Regency crown, and the brim now matches the shape of the Regency brim where it meets the crown, but otherwise this is what it looks like.