I wouldn't let a Comet engineer near my house, I would do it myself, get yourself a compass to make sure you are pointing the dish in the right direction but otherwise it is actually quite easy to set up.
As far as the boxes go the Humax is supposed to be the best but the user interface still takes quite a bit of getting used to. The Humax boxes also receive over 300 Free-To-Air channels, not much use to most people but it gives access to foreign channels, sports channels and others if you sift through all the adult and religious channels.
www.astra2d.com
Ben