What pressures, and diameters are we talking about here? It would be very unlikely an o-ring will like being deformed and sliding in it's groove. An o-ring basically seals by the pressure behind it forcing it into the groove and against the moving component. There is no intended design room for radial movement, well maybe a few thousandths would be acceptable.
A lip-seal design or a concertina design, would be much more capable of following a changing contour, but that would depend a lot on pressures, movement speed, surface finish of the moving component etc. Also, you would have to have the seals manufactured to your specifications. That ain't cheap.
Without knowing more about what you are actually trying to do, it sounds like a fairly impossible task if you want any useful working life from the seal. I would strongly suggest a re-think on the entire design-approach as it is not hydraulic friendly as you have described it.