A good focuser is just as important as the optics. Electronic focus control and precise mechanics are a must, especially for astrophotography. Here you will find a large selection of suitable "hardware".
Lacerta OCTO-PLUS 2-inch eyepiece slide for Newton (guided on 8 ball bearings, with 1:10 microfocus unit and 2" self-centering eyepiece sleeve), for 8 inch tubes
Lacerta OCTO-PLUS 2-inch eyepiece slide for Newton (guided on 8 ball bearings, with 1:10 microfocus unit and 2" self-centering eyepiece sleeve), for 10inch tube