My Last/Current Attempt is the best for me:
2x Ruger Redhawks and a Deagle chambered for .44 Magnum with 150 .44 Magnum Rounds
Remington 700 with 20 .270 Winchester Rounds
M4A1 with 40 .223 Remington Rounds
Mosin-Nagant M44 with 20 7.62x54mmR Rounds
M14 with 20 .308 Winchester Rounds and 20 7.62x51mm Rounds
Flintlock rifle with 25 Paper Rounds
Sig Sauer P230 with 100 .32 ACP Rounds
M1911A1 with 50.45 ACP Rounds
Nail Gun with 55 Nails from Busting up Crates with a crowbar
Firearms Repair Kit
160 Rounds of 7.62x39mm M67
25 Rounds of 00 Shot
50 Rounds of 9mm and 10 rounds of 9mm +P+
100 rounds of .22 LR
I never found any bags or anything to increase volume so with my Otaku with Packmule Trait, i took the Following:
1 Ruger Redhawk and a Deagle with all 150 rounds of .44 Magnum
M1911A1 with 50.45 ACP Rounds
Sig Sauer P230 with 50 .32 ACP Rounds
Nail Gun with 55 Nails from Busting up Crates with a crowbar
100 Rounds of .22 LR and 10 rounds of 9mm +P+
I’m not sure how to go about reloading ammo, but I also found and took a Hand press & die set
Edit: and that round ended quickly cause of Turrets 
Don’t really start in LMOE’s but a bit of advice on your start. If you get the chance, don’t overlook that flintlock rifle, they’re surprisingly powerful, if a bit slow. The ammo is easy to make early game, which is certainly important, just use the hand press you found to disassemble all the other ammo and rip books up for paper when you can. Also maybe drop the Deagle in favour of the M14, something to pick targets off at a distance, but that depends upon your playstyle. I do personally favour having multiple RivTech short shotguns strapped to me for the cool imagery of my survivor
Edit: only just saw your edit, my advice was a bit late. Flintlocks are still cool though, any they will fuck turrets up if you can hit them without dying.
Another sugestion is don’t take 2 weapons that use the same ammo. Compare both weapons and pick the one you think is more useful. The only exceptions is if the weapons have different roles (example: you have a M1911 and that rifle that uses .45 ammo. You can use the M1911 in a holster for close combat and use the rifle for long combat) or if the weapon have a long reload time (like the flintlock rifle, they are really usefull, so i carry a flintlock rifle and a pistol. I use carbine first and if necessary i can finish with the pistol).
Sometimes you get a stupid amount of guns in an LMOE, sometimes not so much. On one particularly miserable play through there was a box of 9mm ammo and a box of .45 but no guns. The only tools of any use to a starting character was a hammer and a wood axe. No good skill books and not much food. Still managed to survive a week on cooked pinecones and boiled water until a zombear surprised with me with buttsecks.
Don’t be in a hurry to jump out into the big bad world next time you start in an LMOE. Part of the fun of it, for me at least, is I can go a lot slower and take my time in an LMOE. If you do get a good amount of ammo/guns in your starting location you need to be stingy with it. The suggestion about the musket was a good one because finding basements filled to the brim with easy to get firearms are gone apparently. Now you might find some easy firearms but most of them are locked up in safes or in reinforced gun shops in the middle of town that are gonna take a little time to get into.
Apparently Giant Black Widows invaded and took over all basements. I’m positively surprised nowadays if I find a basement without one of them piking on the staircase.
Been finding a lot more skill books though, so the pneumatic weapons can replace the .223 rifle I’m gotten used to lugging around for VW beetle sized zombies. Unless those have gone the way of the dodo as well.