Did you look at the modded Minecraft experience at all, before doing that?

Ah good old tekkit. Now there is test pack please ignore which shows promise but to be honest the modding scene slowed down after the bukkit/forge mess and due to the fatigue of never receiving the promised stable api.

The moment ic2 stopped development I lost interest.

Buildcraft spawned factorio however, so my logistic nerd needs are satisfyed :)

IC2 never stopped development, it just became... different.

I haven't but will now

I recommend you start with a modpack.

That said, not just any pack will do. My absolute favorite is TPPI2; I think it's by far the most professional one, but it does require a pretty hefty machine. If it doesn't work, then there are a number of smaller/more specialized packs that likely would.