It really is about how the spinner looks on the plane. There is not a huge weight difference between spinners (unless its purposely weighted).

Personally I'd go with a 2.25 on that plane but I have no idea what a 3" would look like. Not that that plane is scale, but scale planes' spinners don't cover the whole width of the fuse unless it's tapered.

But do whatever makes you happy, that's what it's all about!