I found some boots through CSN Stores that I thought would suffice as muck boots, Diamond PVC boots.
I wear a size 7 1/2, but the boots only come in whole sizes and not wanting to squish my little toes, I ordered an 8. Word to the wise, pay attention to the conversion charts for British/European/US shoe sizes. I received a size 6 in Bigfoot rather than an 8 in women's.
I debated sending them back for the right size, but then thought that maybe they'd fit Mom, so I hauled them up to the lodge. They'll be a bit big for her, but they're useable. I'm kind of bummed, because I really like the gription (yes, that's grip + traction, and yes, it's my word) on them. I guess it's back to Mom's muck boots for me and she gets to use the new ones.
Would I order from CSN stores again? Yep; they kept me in the loop with regard to order processing and shipping and my order got here earlier than it's expected "due date". My only issue is the size chart is not close to accurate. If you're going to order these boots, you'd do good to order a size smaller than you wear.