I would go for sven's suggestion, having a 74 headtube give you a short trail of 50mm, it will be noticeably nimble in corner, but what you gain in corner you may lose in acceleration (i.e. keeping the bike straight while giving it the wellies).
CX bike tend to have a very long trail for stability (around 65mm) by a combination of slack headtube and long raked fork.
I would go for sven's suggestion, having a 74 headtube give you a short trail of 50mm, it will be noticeably nimble in corner, but what you gain in corner you may lose in acceleration (i.e. keeping the bike straight while giving it the wellies).
CX bike tend to have a very long trail for stability (around 65mm) by a combination of slack headtube and long raked fork.