Here are some simulated images that might help in your decision. You can see that aperture is king and that central obstruction is not so important (when comparing a larger scope to a smaller one).
I really like the `clean' look of images through an apochromatic refractor but for maximum visual detail I'd suggest a large well-cooled high-quality Newtonian reflector with tracking of some kind. If the optics are good and smooth and the scope is cooled and well baffled then there is no substitute for more inches of aperture.
