If you’re using a twister as your off hand gun, the BOA is my recommendation. I have it listed in the build thread.
Aiming with the twister is hard to begin with, so you’re better off lining up your shot carefully instead of speed reloading. And since you can’t really shoot from anywhere but point blank range with it, you better make that shot count.
And the 40% or so damage bonus will be multiplicative to money shot, so that’s a pretty sizeable boost.
…And the extra cooldown won’t hurt either.
With the Twister, the Jakob grip is probably the best but the Tediore one is also great since the minimum mag size is 4 anyway … Which will be pushed to 5 with 5/5 Fttb. Basically any combination of parts will work except for any accessory that increases mag size coupled with a grip that does the same, which could push it to 3 shots.
As for auto-loader, I always spec in it regardless, but I can’t pull off the swap dance to benefit from it and AINI1.
I mostly use it to reload my FFYL launcher.