I think the EDG image is the best all round image but to be honest all the images should be like for like regarding there ability with usuals.
sat.xml goes in var/etc
bouquets go in var/tuxbox/config/enigma
As for mgcamd you can with the addition of the extra.url to the EDG image download it from the extra addons server.
To activate it press the blue button once top option and then use the <> arrows on your remote to select it then press OK to activate.
Ferret