I have A91 DAN on the Lotus, which I think works ok as it's a fun car.
Take the point about needing to be a bit classier on the GT. The GT54 DAN plate could either be considered to be fairly subtle if not illegally spaced or it could be considered cheap... Which it is
My initials are DCA, so 123 DCA or DCA 123 might be better types to look for.