Please suggest a blower?

I think you have already answered your own question.

Any blower can do it but it needs the correct manipulation to lift the leaves without the gravel. A quick sweep of the air across the gravel should lift the leaves without the gravel. I use that method to shift the leaves from the flower beds without blowing the soil away, although sometimes a little of it moves.

Good luck

 

I've got a cordless bosch blower that works well in this situation. It uses the power4all interchangeable battery used on my strimmer, hedge cutter and some hand tools.