mountain bike conversion for cross

A friend was nice enough to hand me over a pretty well spec'd 2011 Trek 8000. Since I help manage a cross team I thought this would make an excellent "team bike" for new riders to use if they don't have equipment yet (just the kinda guy I am).

So I want to set this thing up for cross, which entails going 1x10, swapping out for a rigid fork, possibly some sort of 96er franken-bike conversion too.

So here are my questions:

1. anyone swap a suspension fork on a similar model for a rigid? If so, what brand/model did you use?

2. anyone do a 27.5 swap or a 29er front swap on a bike like this? Any pitfalls, clearance issues, etc?

thanks for the insight

J