Momotaro,
I might give the Pathfinder box a look - I debated even just getting that anniversary old school D&D and giving it a whirl. The problem is that "most" of my games end up at conventions, or one-off games, so that's why I'm hesitant to go too RPG-deep into one. I might pick it up and use it for myself and my brother who lives in town or something. I really like Cavern Crawl (with one exception - not a fan of damage charts). Other than that it looks quite brilliant.
I'm leaning heavily toward converting a Warhammer Quest style over, using several decks to allow random dungeon crawl, or GM-driven stuff. I'm also very tempted by icon dice...to give that old school Hero Quest feel (and make it stupid easy to understand at large conventions - "You're attacking, you want swords...you're defending, you want shields".