My son has a 4" Ruger GP-100 in 357. It is fun to shoot and the size is a little bigger than most 357s, but not bad at all.
However, I would really like to have at least one SA/DA that shoots bullets at least 0.400" in diameter.
I have found two guns that meet the second item and yet are about the same size as the first item.
A 5 shot 4" Ruger GP 100 in 10 mm. I have a mini lathe and I am confident I could make rimmed brass for it from some of my well worn 30 Herrett brass (30-30 parent case). I do have a small stash of range pickup 10mm brass.
A 5 shot 4" Taurus Tracker in 44 mag. I have a good stockpile of brass and I have a good bullet mold for the gun.
The Ruger would be low risk to buy, but right now any GP-100 seems to command a premium. The Taurus might be a little more risk to buy, but design/layout of the gun is closer to what I really want. The Taurus also cost a lot less.