Welcome to the yard!
1. I prefer leather myself. Just feels right to me for my knives. I do have two kydex sheaths, but seem to reach for blades that have leather pants more often.
2. Spyderco is the ones I have been carrying lately. I have a couple of them around, however I usually have an endura 4 or police model in my pocket
Most things have been covered at one time or another, however always nice to see new views from new members!