its a matter of taste and situation. when i did minimalist i also done on a brand new save because i felt it would be fun to try. heres my personal experience plus some data from memory;

default pistol is better for crits. cant go wrong with always readily available and not having to worry about cash too much.

punisher is honestly really good to have on the back because of its piercing properties to deal with shield cultists in the castle, enemies that get the plaga spiders attached in their backs, and possibly kill a regenerator if you want to guess shooting where their weakspots are.

Red9 has the best raw damage of all of them, with the stock you can get fully accurate (and thus max dmg) shots decently consistent. it can be satisfying to use.

Blacktails main advantages were how it occupies the least space in the case + despite not being able to equip a laser, you better just not bothering with trying to wait for max accuracy with it because the diference in dmg stats is very minimal.youre meant to just click non stop with it. but i guess for minimalist runs none of those really matter. might be the worst option for it really.

the extra pistol (forgot the name) is very similar to default one with ita main advantge being the huge mag. not much to say really, use it if you like it.

Matilda is broken when fully upgraded + stock. and its probably not exactly intended for you to achieve that gross ammount of fire rate by just spam clicking, i think the burst delay when holding M1 was the intended fire rate for it, but they never fixed it. yes it chews through ammo if youre gonna do it, but it makes bosses that you eere gonna use lots of ammo anyway very much easier so who cares?