Although I have had several different scopes on the telescope mount I am currently using a Telescope Engineering Company 140mm Refractor. TEC is one of the top two highest quality scope manufactuers on the market today. With the addition of an Astro-Physics .75x Focal Reducer the scope has a F ratio of f/5.25, a Focal Length of 734 mm, and a Resolution of 1.14”/pixel. What this means is this scope has a relatively wide field of view with a fast focal ratio that allows me to capture images in a shorter amount of time than would be possible without the focal reducer.
My TEC 140 is fitted with high quality 3.5” Feather Touch Crayford Focuser with a Robofocus motor. This focuser can securely hold up to 10lbs and is essential to serious astrophotography.
If you are in the market for a telescope I would recommend going to http://www.telescopengineering.com/tec/telescopes.htm Yes, the TEC scopes are expensive however, if you are looking into getting into serious astrophotography scopes of this quality are essential!