You will need 2 sets.
A set of full hollow shaft nut drivers and a set of magnetic.
The hollow shafts at harbor freight are terrible, dont bother.
Get the husky ones in a pinch or the craftsman hollow shaft drivers.
And get a set of Klein magnetics with the long shafts.
A 5/16" x 1/4" multi driver is good for posts as the full shank is 5/16" and will go over mini posts on the 1/4" end.