I use a metal kneeler/bench to which I added a thick garden kneeling pad on top of the built in one it came with. Also have the tool holder for it, which also came from Lee Valley so my most used tools are handy. Plus my DH added a piece of pvc pipe wired on the metal frame with the bottom pluged into which I can put a beach umbrella for shade. I have used this for many years it is essential to my gardening. I take plenty of breaks to sit on the patio under the umbrella that is there and have a nice cool drink of water.
My containers for weeds are those collapsible containers they are lightweight and come in various sizes, plus do not take up to much room when stored for the season.