I would like to build a campaign based on a half machine template similar to Kambranex's Machinations in Dungeon Magazine #91. I ran this adventure many years ago and my players loved it, and the idea stuck with me. I never built a full campaign arc to end with a BBEG like Kambranex and I need some pointers.

I can see something like a high level wizard that is absolutely ironhandedly lawful and has made many trips to Mechanus for research. Seeking a way to extend their mortal life he/she finds hidden deep in a library Orcus' tainted books. (reference to The Great Modron March module). I can see he/she is making a deal with Orcus to become a lich but hellbent to fix the mistakes the gods made by mixing all living things with machinery to be a perfect world.

How would I convert the old half machine template to 5.5?

Any good readymade adventures to run that have a high magic/tech feel?

Any other ideas other than a lich that would better fit the BBEG idea?

Any other questions I need to ask or think about when trying to design a campaign?