hey robert,
without leaning to far out of the window I think I can say the SW EQ6 pro is standard in astrophotography for quite some time now.
wherever you look in this forum someone has one and almost every possible problem/improvement has been discussed.
its pretty versatile, rock solid and there is a lots of software support to control/guide it (EQMOD-yahoo group).
there are certainly better mounts but they start some few grand above the eq6 price.
i use mine with a 6" f5 newton and an ed80 f7.5 for AP but plan to ride a 10" RC with the ed80 on it as soon my budget alows it (which thanks to the lower $ here looks rather like next year
).
good luck!