If I were you Dick, I would be seeking a specialist to do the job. Not because I don't think that between yourself and Ash, you couldn't do it, but because they would have something to suit your requirements as that is a fairly complex system.
Something that will come with warranty, peace of mind and that you don't have to worry about installing or checking if you done it right.
It sounds like a job left to someone who has the time to get it right from the start, from experience. I know it would probably cost an extra few bob, but I wouldn't personally go down that path, unless I did it as a profession.