Get a steel framed 1858 in 44 with shorter barrel. 1858 is the only one to let you swap clyanders and is the most durable anyways. Brass frames beat themselves to death (and 1858s never had them), the longer barrels are too big to carry. 44 has the best stopping power, plus it's the only one with a conversion cylinder that takes a moderately common round (if you want to upgrade it. You might not want to though because once it's a firearm, it's always a firearm.)
You can save some money if you grab
https://gun.deals/product/100-cabelas-e-gift-card-82-18-code-baller-one-time-use-only-code-old-users-can-use
then buy
https://www.cabelas.com/product/shooting/black-powder/black-powder-revolvers/pc/104792580/c/104701680/sc/567338580/pietta-model-new-army-caliber-black-powder-revolver/706233.uts?slotId=10
Check your state laws. They may exclude "antique firearms" from carry laws.
Alternatively (and more expensivly), make an 80% Glock (maybe P320) and get a reloading setup to load your own ammo (collect spent brass or order some initial stuff). The parts are on sale right now and for about 519.97+ your choice of sights (35 is the lowest I can find, but there may be even lower) you can have a Glock 19.
https://gun.deals/product/polymer80-pf940v2-pf940c-assorted-textures-and-colors-10999-shipped-after-coupon-m3p
https://gun.deals/product/brownells-glock-19ls-slide-barrel-kits-27999-shipped-after-code-m8y
(You need an upper parts kit and a lower parts kit, but they're not on sale right now)
>>582742
>357 conversion clyinders
What? Even 38 barely finds anything.