As far as your question goes. Something slow and that fragments fast.
Why?
Because you do not want it to go thru walls and hurt someone other than who you are shooting.
Nice toy...if you're not used to it, get lighter loads to get started as it'll help with felt recoil, reduce muzzle flip and aid in faster second (followup) shot...otherwise, knock yourself out!
Really, though...for home defense, I prefer Hornady's TAP ammo, Federal's Personal Defense stuff, and Corbon...but any decent HP will do the job.
BTW...did it come with the optional wheels set? he he
Very nice revolver. Hope to see a range report, soon. The Smiths', post lock, are sometimes given a bad rate. Perhaps you might shed a bit of experience on this as well...thanks, and fine revolver.