longer lasting than what?.... new batteries WILL last longer than old worn out batteries. significantly longer.
as for your "golf cart" batteries, that isnt telling us much other than they are 6v, and were once probably true deep cycle batteries... letting us know the brand of them will share a LOT of information.
I like the conventional wet cell Trojan batteries.
they have a good reputation of being among the top performers, and their warranty is good.
it really doesnt matter what brand or type of battery you purchase, because all batteries, due to their nature, usage, and mis-usage, have a higher chance of premature failure than any other component or system on your boat.
the more batteries you have on board, the greater chance you have of one or more of them failing well before their normal life expectancy is reached.
and one bad battery, if it isnt taken care of reasonably quick, can bring down the other good ones that are in the same bank with it.
buying a good reputable brand will lessen the chances of that happening.
as for life expectancy of the batteries, it really depends on the health of the entire system rather than the type of the battery you buy.... some conventional batteries can last 10-12 years, and some of the "new technology" batteries can be taken out in a couple years by faulty chargers or improper use... but all things being equal, some of the newer technology can offer some advantages, but again, its depends on how the batteries are going to be used and treated.