Granada the 100mm f/9 refractor is a poor choice for AP. A much better choice would be this 6” maksutov newtonian
http://www.iceinspace.com.au/forum/s...d.php?t=162004,
And you have the change to buy the EQ6-R mount.
You could conceivably use an 8” f/4 newtonian but that is likely to be more challenging.