The knee pads I wear probably lean more towards mtn. creek kind of stuff, but I use them for everything and find them comfortable. They are the Race Face Ambush D30. I think they might even be DH rated.
Not going to lie, they are bulky, but they are still comfortable and don't bother me pedaling. One thing I really like is you don't have to slide into them. You can put them on or take them off without dealing with taking your shoes off. I also toss mine in the washing machine and so far no issues, though it probably isn't recommended. They take abuse, and most importantly, they work. They stay put when I go down and have good coverage.
Even if you go for something smaller, def check out the D30 technology. Its flexible when not stressed but solidifies on impact. I don't love my elbow pads so no recommendations there, but personally I'm inclined to go lighter on elbow pads vs knee pads. My knees get the worst of it when I go down.
Take my input with a grain of salt though, I've always worn a full face helmet and pads on Motorcycles/dirt bikes so for me it feels normal to wear the same on a bicycle.