Run 1.7 with just Thaumcraft 4 and Rotarycraft.
Thaumcraft has interesting mechanics, beautiful textures, a guide book, and the nice storyline of trading sanity for power. It has believable automation (golems), handy trinkets, great armor, and a need to have handy trinkets and great armor (exploration and fighting, plus boss fights). IMO, TC4 is one of the best mods ever written, even if the research mechanic gets tedious after the second or third time through.
Rotarycraft is science and technology, as opposed to the Thaumcraft mysticism. The power system is straightforward and simple enough to learn, but challenging enough to provide ample gameplay once you get it. It has answers for most problems, while encouraging supply chain and resource management. The end goodies are enough to make you feel like it was worth the effort while the effort is challenging enough to make you feel like you earned the rewards.
Throw in Storage Drawers and maybe Ender Storage for convenience, and you have all you need. If you're worried about the boredom factor still, toss in Twilight Forest and its progressive combat challenges.