Lately I've been playing Gregtech Community Pack Modern, which does seem like it's what you're looking for. It's a casual (peaceful mode) Gregtech modpack.
Finding modpacks to play in general has been difficult for me, but I recently stumbled upon this website that gets modpacks from curseforge/modrinth and lets you search for modpacks by version, mods, and categories.
(I am not affiliated with either of these projects)