Best option for finding consumables after main branches
I swear that some day I'll stop with my needy posts, but today is not that day. So I have (I think) a quite strong GrEE^Ash at XL27 with lots of good spells, including Polar Vortex, Ignition, and Shatter. I've cleared Zot 1-4. If I had even a single potion of brilliance, I'd think I could just blast in, take the orb, and get out. But alas I do not. I've already cleared Crypt, Vestibule, and Slime:1. So I'm wondering where my next best option or options would be for seeking extra potions (could use more haste as well, as I have only 2). Or should I just suck it up, and go for it?
I've never dipped into any other parts of the game other than what I've cleared here, so I'm not clear on the relative dangers or potential rewards of Slime, Pan, Abyss, a few floors of a Zig, or Hell branches.