Muds are hard to kill you could keep them in just about any container and change the water out like once an hour.
Shrimp are a bit trickier to keep alive especially in the summer heat. Just about everyone on here has a different method. I don't like having a flow troll to drag and slosh around in my Yak and I can't stand the noise pumps make. I like to fill a quart bag with ice and double it to prevent leakage, then I put this in a small soft side lunch box cooler. Put your live shrimp in this cooler and they "go to sleep", take a shrimp out an hour later and they magically wake back up. Don't ask me how this works? I read about it in Florida Sportsman a few years back. The trick is not to let the shrimp sit in the water from the melting ice, this kills them. You still lose a few but, this method for me is very Yak friendly.
With mullet your only choice is some sort of flow troll like device those guys go belly up quick! I honestly don't use them much if ever in my kayak.
I also fish arties most of the time but, I am not too good for old fashioned bait fishing
Hope this helps and good luck out there