Large MTB shoes, Cassette, & cleats

Hey everyone,

I'm looking for a set of MTB shoes. I wear a US size 15 which, I think,
is a 48 European. If you have a set you would like to get rid of or
know of a place I can pick up a pair for cheap I would appreciate it.

I'm also looking for a Deore XT 8 speed cassette for my bike. My
current cassette has a hiccup when I shift into 6th and the smallest
sprocket jumps if I really get on it when riding on the road.

Also I have a set of Shimano PD-M747 clipless peddles. Where would I go
about getting a set of cleats for them?

M. Prindle