9.5 actually refers to the Ofna 9.5 buggy:
http://ofna.com/manuals.html
It's totally separate from the Hyper series. However, some minor parts like such as those for the differential are interchangeable (1/8 diffs are often interchangeable between different companies).
In my personal opinion, ceramic bearings throughout the car are only worthwhile if you'll be getting into hardcore racing. You can get standard bearings for about $1 each, depending on the size:
http://www.avidrc.com/shop/?action=i...=1&prevstart=0
Comparing the ceramic bearing kit to standard bearings, you can get three times more standard bearings for $90.
Hoboa (manufacturer of the Hyper series) typically uses rubber shielded bearings. These last the longest of standard metal bearings, but also have the most friction. The bearings themselves won't spin freely, but when attached to the diff they should spin for a bit. If the bearings feel at all gritty then it's most likely time to replace them.
Those screws are the exact ones that come with the servo, so you can bet they're the right thing.
How much play is there between the center diff bearings and the mount?