Thanks mate, my google fu isn't doing that well due to working off a mobile as home internet hasn't worked for the last week, big thumbs and small screens don't mix.
I don't actually have a WA M4, I've got the DAS M4 (at least just waiting for customs for it) and was planning to stick on a 16in barrel (after I've checked it works well in stock form), and wouldn't mind having a mess around with it as soon as possible.
out of the three versions above, which one do you think is the best one overall?
thanks.