I bought a JPS rollbar and it is for show only. If you are looking for safety best discuss it with your builder if you are at that stage.If it is an aftermarket/already built install, take the car to a race shop that does this sort of thing daily...
When you use the word 'safety' your expectation of a rollbar's performance is best handled by professionals.
Check the back of a few mags for shops that cater to the race car circuit. If you are an SCCA member or know one, get a copy of their 'Wheel'publication. It has some specific advertisers/builders of rollbars in it.
MM