Trying to Buy A Fully Loaded Kayak Set up for Around $400

[Salty]

With that budget, it will be hard to find something with everything you're looking for. Since you're on a budget, here's a budget-friendly bait system a friend and I made. They're great for cruising around the harbor or in calm water, but it's not something you'd want to be dragging around in strong currents or headwinds. Super easy to build. All you need:
5g Bucket
Pool noodle
Rope
Large zip-ties
Drill w/ 1/2" bit
If you want to go crazy with it, I cut out the lid, then used a propane torch to smooth out the edges of the lid. I also used it on all the internal drill holes so there are no sharp edges for the bait to cut themselves on