There are some monthly type clubs out there, but I've never tried any. Most of the ones I've looked at don't really have anything special to offer. There are some single barrel groups that buy barrels for members, typically with a monthly fee through something like Patreon that gives you access to purchase bottles from online stores that come from the barrels that have been purchased. I've been a member of a few of those with varying results. Private selected single barrels, be they from clubs, stores, or local ABC boards are some of my favorites because they are always different. Some of the best tasting bourbon I've had came from barrel picks. Keep in mind, having liquor shipped from out of state is illegal. There are stores that will do it due to a gray area with shipping beer and wine, but it is technically against the law.
If you have exhausted all the brands and expressions at your local ABC store, there are a few other options. One is to do some driving. Virtually all of the bottles I have come from somewhere within driving distance to my home, and it's not though special hookups or anything, it's just driving around seeing what stores have. Typically each ABC board has a flagship store, and these normally have the best bourbon selection. Here in Wilmington for instance, that's the Porter's Neck store (though that may change now that the new fancy Wrightsville Beach store is open). That's your best bet for finding things you haven't tried. Another option is to check the special order list (
https://abc.nc.gov/Pricing/SpecialOrders), and have your local store order things from that list. Those items aren't the rare allocated stuff, just some things that aren't a part of normal deliveries (Belle Meade is an example from that group). Now one thing I've found is that the flagship, bourbon centric stores are actually taking the initiative sometimes and ordering these things for their store to help their selection. There's lots of good stuff on that list to try.
Just a guy on the sunshine squad.
The Gatekeeper.
Homer Dumbarse.
StateFan2001 will probably respond to this because he doesn't understand how ignore works.