These capacitors are not like the large 1 Farad capacitors in high power car stereo applications. They are located on the power circuit between the R/R and battery.
The price is for the capacitors only. They are not large. About 3/4" diameter. I can place in small bubble envelope and mail for around $2-$3 I think. Haven't checked out furthest location yet or cost of shipping materials.
Capacitors always have a charge on them unless discharged.
The bracket would be extra. I have not yet had a chance to investigate this yet. You could replicate what the other guys have done with a simple piece of strapping steel, u-bolt, and associated hardware for now. I need a chance to sit down and design something in the computer, create prints and get quotes if feasible Will post more info on this later once I have a full kit figured out.