I'm searching for a couple of miscellaneous items...waterproof boots and kneeling pad

For the boots are you thinking Wellington boots like Le Chameau?
Country Life Top 10: Wellies - The best wellington boots you can buy

 

For the mat something like this?
Outdoor Changing Mat | Camping Mat | Folding Mat - Adventure Mat

 

I use knee pads, any hardware store would have 'em.

 

I can attest to that...and to the fact that my waterproof boots also filled up with icy water from the Atlantic Ocean.

Glenn

 

Yoga mat, HD knee pads tilers use, boots depend on how deep you need. Have fun

 

There are lots of "best of lists", here's is another, The Best Rain Boots for Men and Women for 2019

Years ago we made our first trip to Alaska and we wanted to take waterproof boots with us. Our Alaska friends told us to wait, and if needed, buy 'em up there as they know best what works. In the end, we never needed "Ketchikan sneakers" and saved ourselves a lot of money.

 

Terri, I just tried both Muck and Bog brand boots, wanted them for hiking in wet woods. Went with the Bog brand, found them very comfortable to walk in. The Mucks hurt my feet, but everyone’s feet are different. My daughter has Bogs, she likes them a lot. If you visit Bogs website, they’ll send you a 10% off coupon. I tried the Mucks locally in a farm/sports store named North 40, maybe there is one near you. Had to order the Bogs online, Zappos has them.