Hate to do it but I have to shoot down that JBL.... Some of their wood guns are nice, but you can get a better gun for a decent price with all the different options on the market.
I did some reading and notice that alot of divers out your way use AB biller guns for halibut guns as they have a heavy shaft and good punch, but lack in the range department.
If you are looking for range and power, I would consider looking into the Riffe Euro wood guns. Very nicely built, I have one in cozumel that I use for barracuda, mahi, and grouper. I use the 90x.
Cressisub geronimo guns are also very nicely built, I havent had the opportunity to shoot one yet but checked one out the other day at my local shop.
Other guns I would recommend looking into -
OMER, Sporasub (their instinct pro is a nasty gun, I have one and love it) Mako, Aimrite, Rob Allen. Euro/railguns are easy to load, easy to swing on a fish and extremely accurate, and you wont be blowing a hole through a fish like you would with an AB Biller ( I had a 32, every fish I shot had a giant hole in it) I still own a 48 that I use as a reef gun in cozumel for poking in holes.