https://www.amazon.com/dp/B00266QM8K is actually the one I was thinking of. There are a few sizes, including a 3.9" wide at $80, but I would say the 8.2" x 2.8" x 2.4"H is probably the best bet at $33. Gives the width mostly while having quite a bit of life in the height.

Pair it with a cheaper low grit for trueing the edges and maybe some sandpaper for honing higher is you wanted to, and it'll work great.

Cheap low grit combo's are very reasy to come by and if only used to true the edges/debur before lapping on higher grits, should be fine not running the whole length of the stone (use the width, not the length of the stone). https://www.amazon.com/dp/B072NSC844 is $6.34 - 6" x 2" x 1". Could still fit a fair few blades and chisels on the length as well.