reconditioning jafsa hammer and buying another – go for a top brand?

rebuilding hammer + buying another - go for a top brand? We're in central Mexico, working in a mountain town with a lot of limestone and volcanic rock. We bought a Jafsa hammer for the backhoe 4 years ago and it's finally given up on us. It worked pretty hard, though. Jafsa is a local brand. It used 12 to 25 gal/min of oil, had 190 ft/lbs of force, and struck 400 - 900/minute. They are meant to copy Montabert models. To get it rebuilt we will need to send it to Monterrey, about a 10 hr drive from here. It was our first hammer. We don't know the rebuild company, it was just the best one we could find online, hopefully they will do a good job. They are selling Maverick hammers. We are trying to choose a new hammer, so we can have the new one for upcoming road construction contracts, and the rebuilt one as a backup. Would it be better to buy a quality name hammer, like a Kent, maybe? Kent seems to be the only big name easily available here. The Maverick 750HSP hits a lot harder than the Jafsa - the chisel is a lot smaller - and the oil flow it needs is a lot lower. Would that make it better for breaking up limestone and volcanic rock (the volcanic rock is full of bubbles, which makes it splinter instead of split, it's a mother to demolish). Clearly, we don't know a lot about hammers. We'd appreciate advice.