I've seen a few early access packs, and I have to say.. if resources are scarce, you don't need a mod PACK... you just need ONE mod. I've been having a whale of a time with "Lost Cities" I first played it on 1.12 unstable.. but as the name suggested, it wasn't stable (d'uh Sherlock!)
Lost cities changes the way the whole game feels though. I created a very small mod pack , Lost cities, immersive engineering and early power gen and that was it. You don't spawn in a wilderness, but instead in (or near to) a ruined city complete with sewers , roads, bridges and underground rail. it's all damaged and CRAWLING with mobs. every building has at least 4 or 5 spawners hidden around inside. It's a fairly fun environment. It would work great with Zombie Awareness (if it ever gets ported to 1.12 that is) It's "post apocalyptic" and you feel like a Fallout scavenger rather than a minecrafter.
if you're looking for a new 1.12 modded experience, I'd suggest either a light 1.12 modpack or roll your own with Lost cities as world gen.