get yourself a wobble board
I'm riding with a full rupture ACL+MCL right knee, and a grade 2-3 ACL+MCL left. Neither have any major cartilage damage and neither have been repaired. Here's my 2cents
1) I wear proper rigid ACL specific braces on both legs, and with those things cinched down I'm good to go, probably stronger than pre-injury. They allow a little movement in the joint, but the idea is not so much movement that you load up the intact ligamnents and blow the whole joint apart
2) While I think that strong legs = strong knees, one thing to consider is how 'fast' your muscles are, especially in the tiny fast twitch stuff going on right around the joint. I had a really good physiotherapist that explained how these muscles 'sense' the position of the joint and tense up when things are getting out of line. The best way to (re)train these muscles is with a 'wobble board', like a round piece of plywood half a ball in the centre. You stand on the board and it rests on the ball on the floor. Pretty 'tippy' thing, but you should be able to balance on it indefinitely while doing squats and stuff. Then you get someone to try to push you off of it by giving you quick shoves. Once you're good at that, do it all with your eyes shut.
The only time I ever have trouble is slow speed falls, like if you get bogged down on a traverse or a straightline on the flats in deep snow. Beware of these situations and always be ready to have stiff legs and keep them underneath you. I think you're less likely to re-injure when you're really given'er than when you're going slow.
Oh ya, about your originl question regarding equipment: use whatever you want, I say, because none of it is really good for your knees, and I think knowing how to fall is more important than what gear you're falling off of.
Good luck with it!
DG