Jimbo,
It's been some time since I've smoked any fish, it's hard to get the Zig Zag around them

, but I used to use a ready mixed brine. I stpooed using that a long time ago and started using an Italian dressing to soak prior to smoking.
I am thinking of using my Carne Asada brew to smoke with next time.
Mike
PS, I would think Olive wood be a great wood to smoke with, lots of oil in it, very fragrant as well.