If you're talking steel, locally we use the same plates and poppers that other disciplines use. CAS regs pretty much regulate speed of projectiles. My 44 cowboy loads run around 700 - 800 or so if I remember right out of 7 1/2" Vaqueros. Been a looooong time since I did any chronographing. SASS webstie has the velocity limits posted , I believe.
We have made up some cardboard cutouts and sketched them up as appropriate (bg, no shoot, etc).
As for styles, mostly I've seen "the usual suspects"; bg holding weapon, kid with toy, lady holding shovel and that ilk (B5 type targets).