JL has some funky impedances on some of ther subs, like 3 ohms, and stuff like that.
There was a reason for it... 3 dual 6ohmvc drivers could get you to 1 or 4 ohms , 2 dual 6ohmvc drivers would get you 1.5 or 6ohm , and 1 dual 6ohmvc would get you 3 or 12 ohms Nominal ratings, ofcourse...
Same with the 1.5 vc's... it's all about having flexibility
The surround on the JLs is a hybrid foam/rubber with excellent uv protection
Also agree with these guys on the subs vs power.. I know of several boats with w7's and matching power that have performed well for years... Unless you plan to put atleast 700 watts to an L7 get L5's.....
2 W6v2's will put out plenty of db's... Heck, just one rocks