i use a set of fox ones that only have two straps around the calves so the knee bit can flap around a bit, which is fine if wearing long trousers, but not the most secure otherwise. But because they are strap on rather than the sock style put your foot through I can put them on without taking shoes off, and make them as tight as I need.
before I got them though, I used a set of blokes elbow pads on my knees and they worked fine too, and then I was clipped in so didn't need lower shin protection really anyway... but this is all me being stingy and not buying my own gear, just using odd bits handed down...
I would say as long as they don't wander about when you are pedalling most will do the trick. But if it is for XC riding then something you can take off easily for the climbs might be good - less hot and sweaty anyway
glad you are back riding Anu 