What happened to Hack/Mine? That had areas which scaled depending on how far away from spawn you were, with stronger mobs and better loot.I would love [to make] an adventuring pack, myself, but there's two major problems - there's no long-term benefit to far field adventuring, and technical issues. Perhaps if we had some sort of mod that generated more exotic structures/offered better rewards based on combined coordinate value (abs(x+z), higher result=better worldgen/rewards) this would give some incentive to venture further out into the world. Unfortunately, because of how worldgen works many servers instead make fixed borders, so exploring becomes virtually impossible. Flight also makes exploring a trivial matter, because there's absolutely no challenge if you just fly over everything. Sadly, most popular mods offer some form of limited or unlimited flight ability. Teleportation/'return home' functions also make adventuring much less challenging, and the latter still anchors the player to a central spot.
One mod included in 1.7 Unstable that could make adventuring much more viable is RandomThings and its Spectre Dimension. It's a (I believe) 14x14x14 personalized space that you can teleport into/out of at will using a key. Players can thereby store important items/machines/etc. here and yet still go adventuring without too much worry about losing things.