Page said:
One problem - I don't know whether to run 1E or 2E!
Good question.
May I recommend Troll Lords Castles & Crusades? The authors had sentiments very much like yours! They were very nostalgic for 1E, but desired a smooth system with quick resolution mechanisms. So, they streamlined D&D 3.5 and repackaged it, under OGL of course, within an obviously nostalgic-for-1E structure.
They even dedicated their "Player's Handbook" to the late Gygax.
C&C also has the advantage of being (as someone said) 90% compatible with 1E and 2E materials. Conversion of adventures can be undertaken quickly. There is a nice assortment of classes, including our old favorites such as Assassins and Monks, with new ones, such as Knights, thrown in for additional flavor.
I'm actually using my own class system, one I grafted onto 3.5, but that is another matter, of course.
Anyway, go check it out! If you are skeptical, there is a PDF called the "Condensed" version of the game system. It gives you a very nice overview and enough rules to start playing.