The problem with the pneumatic nailer, if you can get it to drive a nail in the concrete blocks, the interior of the block will flake off leaving very little holding the vinyl siding.
I did a concrete block house in the mid 80s with masonry drill, plastic anchors and screws. It burned up 2 masonry bits but the job went very well and is still looking good to this day. They had tapcons and aj's back then but the price was exhorbitant.
I have done some jobs on furring strips too and that's a mess I'll never subject myself to again.