V105s are a nice tyre for year round use. A lot less grip in the warm weather but better in the cold and very wet. Also, the sidewalls are a lot softer than 888s so they don't tramline as bad. If you use your car in the winter they would be my choice. But all four, not just rears!
If you have been happy with the 888s and only use the car in warmer weather I would just stick some 888Rs on the rear. They work perfectly fine with 888s on the front - I know because I did exactly that.
Bilstein refurb is the way to go - if you like the way the car handled before don't fix something that ain't broke!