Hmmm.... "ultimate, go-anywhere, do-anything combat revolver"
Smith K Frame ... a 4" bbl'd M-66 (Don't want an "L" frame for its add'l weight nor the full length under bbl. lug for the same reason.) ... find one with a well worn-in, smooth as a baby's behind, DA trigger, but with "tight as a tick" lock up....give it adj. sights that stay put once adjusted...white line front, white outline rear...or tritiums if you can provide 'em on a Baughmann ramped front...give me a narrow smooth combat trigger and a narrow hammer too...and lastly, add a pair of smooth 'coke bottle' grips further sanded to fit my grip EXACTLY with some burl in the walnut or rosewood...closest I've found are vintage Ropers, but Mikulek's combat offerings are a very close 2nd place.
Loads: I'd like something on the order of the old "FBI" .357 158 gr LSWC-HP. Put 'em up in .38 special brass for easier, more reliable ejection, and make them with a soft enough LSWC-HP that'll expand at 950 fps from a 4" tube. Of course I don't want any leading from those hefty slugs...better gas check them. Stuff them in Safariland gen ll speed loaders for ease of reloading too. A pair would do nicely.
Leather: An open top, snug fitting Tom Threepersons that needs no thong nor strap. I'll wear it at 4 o'clock, OWB, thank you very much. Make it a black one, maybe with a bit of stamping for BBQ nights...& black hides well with dark trousers, I find. Cinch it up with a 1-1/2" wide 10 oz. gun belt with a good, tight fit between holster loop and belt. That width will fit through all of my belt loops, & still support that 38 oz. revolver with a cpl of speed loaders thrown in. Make it up with a dull brass or silver buckle that won't reflect light in an alley. And be sure of the fit of the holster loop/ belt, I want it snug; I don't want that rig sliding around on me...