Some suggestions

[Krusty]

It is the same engine+supercharger that the A6M5 has, minus the ejector stacks.  Most people don't realize it, but the A6M5 has pretty decent performance at altitude.

What most people don't realize is that, while it had the same engine model, it did NOT have the same performance. It was only about 10mph faster than the A6M2, and that performance was gradually reduced as they added the wingtips bad, added back the removed fuel tank (that pilots missed once it was removed).

Outside of the weapons loadout, it's very VERY similar in overall performance to an A6M2, despite having a different engine.

EDIT: It just had different power chart peaks, because of that engine.

[Karnak]

Where is the WEP then? I thought that most of the time at least, a supercharger meant WEP.

Superchargers don't have anything to do with WEP.  Superchargers are blowers that feed the engine higher pressure air than ambient so that they do not become oxygen starved.  The gears people refer to are blower speeds and determine how much air pressure is added.

[gyrene81]

Where is the WEP then? I thought that most of the time at least, a supercharger meant WEP.

WEP = War Emergency Power. It is simply a way to temporarily boost the power output over full Military Power (i.e. over 100%) of an aircraft engine that had superchargers and/or additive injection systems. We tend to use the term very loosely in cartoon pile-it world.

[Eagleclaw]

I know what WEP is, I just always associated WEP with superchargers

[gyrene81]

I know what WEP is, I just always associated WEP with superchargers

Now that you're better informed, you don't have to. 

[Eagleclaw]

Haha, ty Gyrene 
But back to the plane selection, what are your thoughts? Doubts? etc.

[gyrene81]

Ki-43 hands down top of the list...the others are too iffy.

[humble]

The problem is there are relatively few planes with broad appeal left to add. G.55 clearly #1 in that regard IMO. Ki-43 is essential for scenarios (along with the LaGG-3 & D4Y). Once beyond those along with the Betty and other early war bombers your into a variety of "niche planes" of various flavors...personally of all the other planes not in the game I'd love to see the Hawk75 since it was the single most important plane in the west on the allied side in 1940...