If you guys are still taking mod requests,
AM2 and
Mekanism would probably add to both the magic and tech side of things.
Ars Magica 2 adds spell crafting, a bunch of mobs, and even a few bosses. There is world-gen involved with the mod, but most of it are plants needed to craft things in the mod that can be obtained easily in a new chunk on the surface. The spellcrafting isn't OP I think, and players are limited to a certain "mana cap" until they level their mage abilities up and increase it. It also adds a new GUI element to track your mana, spell burnout (a feature of the mod), and your mage level, in case that matters. It shouldn't get in the way of anything already there, though.
Mekanism's forum topic has a better explanation than I could possibly provide, so I'd recommend checking it out, and it even has a wiki if you're more interested.
I think these mods would make it more fun to play if people took the time to get into them, but i can understand if you don't add them. Anyways, thanks to you guys for hosting this. I'm having fun regardless.