The history:
"It may also be said, 'Before Alamein we never had a victory. After Alamein we never had a defeat.'" -Winston Churchill
Mike, being more of a historical grog than I am, may well hop in with more detail, but very broadly this can be said: the series of battles at El Alamein, a relatively unimportant railroad stop at a chokepoint between the Ruweisat Ridge and the sea 66 miles from Alexandria, between July and November of 1942, stalled and then turned the tide of the entire African war against Erwin Rommel's forces, ending the Axis threat to Egypt and points east and denying them access to the Suez Canal and the oilfields of the Middle East. Sort of a big deal!
Why 6mm? As we discussed in the other thread, 6mm is nice because it allows you to collect forces at the company level cheaply, and (at least as importantly) lets you play with company-scale forces on a 6 x 4 table while still allowing for maneuver and tactics. Even from the relatively-expensive GHQ, a force consisting of a supported infantry company and a tank company will set you back something in the neighborhood of 100 USD, and if you go with CinC, which has a less absurdly-complete catalog and slightly less absurdly-detailed models, it could be done for even cheaper. I also happen to have a desert-themed board and terrain in 6mm which I collected for Epic, so there's another expense we can save.
What rules system? The nice thing about historicals, of course, is that if you collect yourself a historically-accurate force, you'll be able to use it with pretty much any game - the only issues are usually basing*, and how a given game represents commanders and such. As such, I have a couple systems in mind. The first is Blitzkrieg Commander, which is based on the venerable Warmaster system, and the second is Too Fat Lardies' I Ain't Been Shot, Mum, which has a card-based activation system and lots and lots of fog of war - which is, if you know me, something very much in its favor in my eyes.

What forces? Mike has decided he wants to collect Kiwis, and I (taking a look at deployment maps and such) am at the moment thinking of an Italian bersaglieri force. You may laugh, and Mike already has, but one of the nice things about the rules systems I'm suggesting is that they take a more "realistic" and less "cinematic" approach to rules, and in particular national special rules, than something like Bolt Action, which by all accounts hamstrings the Italians to near-unplayability in service to ideas of their low morale and low troop quality that have more to do with movies and TV shows in the years after the war than reality.
And that's about as far as our discussion has gotten! If anyone else is interested in joining us, by all means, feel free.

*Quick note about basing: At the moment I'm thinking of basing up rifle squads of 8-10 men on 60mm x 30mm bases, and everything else (weapons teams, tanks, leaders and the like) on 30mm bases. After putting my Napoleonics together, I really like the "feel" of this base size, both in terms of tabletop footprint and semi-realistic distributions of men on the base.