Copied this from the local boards here in Saskatchewan which was originally posted by Chalcus of the PDW squad out of Regina. Gives you an idea of several different patterns in the field. In each of these photos we stood on an open trail, then the side picture we stepped back about 10' into the bush line for some slight cover.
As for you mags on the MP5, I'm sure if you contact manufactuers like cpgear they can give you a price on custom pouches for them to match your gear, especially if you stick with the cadpat you already have.
Otherwise OD blends in pretty decently with cadpat as well in small sections.
Maybe look into a chest rig system, with a MP5 mag leg pouch.