QUAD: Starboard or JP ?

Hallo guys,
after a season during which I've decided to buy a twinzer a new stuff comes out:the quad!
From what I've heard it should be even better but now I'm a bit confused...
Can you please describe the difference between twinzer,tri fin and quad?

I use to sail my Euro wave sessions in spots where the main sail is the 4,7.Wind is side on,side and,sometimes,side off.Waves height is 0,5 to 3 mt (mostly 1,5-2).They can be huge but almost never aggressive.I mean,even if it's big,it tends to not last long.
I mainly focus on waveriding instead of jumps.With my single fin I use to have 2-3 bottoms on a average wave but I have to work hard for it.
Tested a twinzer and in light air/smal waves had 3 bottoms where I would dream for a good ONE if I've been on a single fin...
That's why I want buy a multi fin board.

Just to have a better reference can you help me to understand how choose the right size?
I mean,guess to have understood that twinzers need to be bigger than single because of the narrow tail,so when you use a "classic" 75 l single you have to go for a 80/2 l twinzer.
What's up with quad?

Another question regards the different fins set up between Starboard (bigger fins forward) and Jp (bigger fins rear).
Why that?Different goal?Different feeling?
Can you hel with that?

Thank you