If I could, I would go totally cyborg.. i'm talking a 25 foot tall robot with my brain safely contained within it. even it it only doubled my brains lifespan I think it would be worth it, 160 years alive is better than 80 plus i'd be a giant robot!!
Cybernetic technology has come further than you might think, I've seen articles on brain operated computers and people with prosthetic limbs that can actually feel with them!!
One of the lecturers at my university had chips put into his arms and stuff and he could control a robot arm over the internet!!
this is a long way off the kind of robotic alteration i'm thinking of, but give it 50 years and I reckon people will be replacing body parts for machines by choice, not neccesity