Advice?

I've never been on the cutting edge of fashion. I'm usually at least one season, if not two seasons behind. Took me three years to actually buy anything in Chocolate - the "new black". I have been wanting a mid-length wool trench coat in pink for two winters now but have only ever see them ON PEOPLE, not in the stores.

Well, that temptress Ann at Gorgeous Fabrics got in some beautiful coat fabric and was nice enough to point out Vogue 8346 , which is the exact coat style I've been coveting - fitted bodice, flared skirt. I like View B (the red one in the picture) which is just about knee length although View A is adorable, too. But then, Gorgeous Ann had to complicate things by having TOO many cool shades of pink. I think I've just about decided on this one but I haven't ordered yet.

Before I invest in the lovely flannel coating, it occurs to me that this would be a great project on which to make a muslin first. So I don't muck up sixty-something dollars worth of wool. I want something inexpensive as I don't expect to end up with a wearable muslin out of this one, but heavy enough that I will get a good idea of how the fabric will drape and a true representation of the style. Any suggestions on fabric choices?