I currently operate a king air single pilot that has two efb's. Fujitsu's with the spin around keyboard and jeppview on them. We were operating on one and using paper as the backup. Now we operate two because the cost of the paper paid for the laptops in just over a year. We couple the EFB i'm using with xm radio which is bluetooth connected from a server in the back of the plane (this is for domestic usa and canada only)
We also use a small gps about the size of a pack of cigaretts and it is also connected via bluetooth to the efb. The position and situational awareness it gives us is unreal. It shows the plane on the taxiway diagram and also on the approach chart. A real plus.
Since we visit the same airports I do have a 3 ring binder with all the charts needed behind the pilot seat. This is my last line of defense if both efb's fail. I've never used it but it is nice to have for some reason.
I'd highly recomend getting one with bluetooth and linking it up to the GPS on the dash.