Just a suggestion...I had horrible troubles getting my AW 1.20 Yak 54 to meet "CG" specs. It was god awful tail heavy. Rather than just adding weight for the purpose of making the suggested "CG" position, I also added horsepower to throw the weight around. I put an OS 160 in the plane and the "CG" came out dead on without having to move all kinds of stuff around.

I would go with the Evo 55...BUT before you drill the screw holes, check the "CG" while shifting the engine further forward on the engine mount. When you find the sweet spot, lock her down.

I would never add weight on any aircraft without adding horsepower, too. Just me, though...