Halo 1 is the best, i've been playing it for years.
I used to play on my PC with this:
I was dying to try it on my macbook pro once my desktop died, but for some reason even though i installed the mac software it still wouldn't actually work. Maybe i did something wrong because it's supposed to work on mac. But if you can get a hold of one of this nostromo speedpad and get it to work i would highly recommend it, it really helped my game. You can customize every key for each game you play and it's got 2 adjustments to fit your hand.
As far as the mouse, i found with halo a simple 3 button cord mouse gives better performance than my 8 button laser mouse.