What's the deal with the different types? I'm looking at the xlr connector but not sure what that means to be honest.

The different types refer to the different kinds of batteries you may use with the light. Some batteries only take XLR connections. Avoid cigarette-lighter type connections and go with XLR or the Anton Bauer tap. They are proven, professional solutions.

ok which battery pack is best with this?

Anton Bauer batteries will give you no trouble whatsoever. They are professional batteries, but they are also quite expensive. It depends if you want to buy a battery belt or a brick-type battery that attaches to a strap. Bescor batteries are cheaper and should be OK, but you'll have to take better care of them.