I would like to make a cruiser, but am wondering what the size range is. My two current ideas are a anti-ship heavy weapon cruiser sort of like the one currently posted, or a more supporting cruiser that's heavy anti-missile and fighter/bomber with a medium armament for discouraging smaller ships from closing to it's pair.

This is a weapon question, which is a hypervelocity missile launcher.  The advantage is an additional 0.2 cee acceleration from ship's velocity, increasing the range and speed, but reducing the mobility of the missiles. Secondly, the mounts must be built into the hull, and only have a 60 degree firing arc. Heavy missiles must be used, and the acceleration trades payload size for speed. 

Other than that, I am still working it up.