MTB project – Trek ZX 8000

I’d like to turn this into a touring style MTB, I’d like to switch out the the forks for some rigid ones and change the sticky gear changers (twisters) to some click shifters (not sure of the name). Dutch style bars would be cool. I don’t know the fork size and unsure of how to measure the wheels say 26

So I’m Looking for any ideas on what other people have done with vintage MTB’s – I’d like a comfortable riding position so any bar & stem recommendations would be amazing, it’s got some nice parts on already that I’d like to keep such as the STX RC cranks.

Thanks from England