Tony,
The 60D is at the top of Canon's consumer-level cameras.
Its rugged body sits in between the entry level systems and the 7D body. That is, it will feel like a camera in the hands, and, not a toy.
The articulating screen is a bonus for doing macro work and/or astrophotography -- you don't have to get your neck into weird positions to see the screen. Just swivel and set.
The 75-300mm lens is alright for happy snaps. With Canon, if you want quality lenses (build, sealing, contrast, colour, sharpness, etc.,) you really need to spend money on L-series lenses.
The 75-300mm lens will not be so useful for astrophotography as at the 300mm lens it runs at f/5.6 (from memory) and is full of aberrations. By the time you stop it down to f/8 to improve corner performance and sharpness, it's too slow to do any real astrophotographic work.
http://www.dpreview.com/reviews/canoneos60D/
For a little more you could probably get the 7D.
H