You should see the one my dad made. He made one based of a discatcher but without the band and it is sweet. Also I know a guy that made copies of a Mach V to put on his private course. Then again both my dad and that guy had the resources and shops to do it.
I will throw my two cents worth for the Instep basket. I added the extra chains and it seems to catch disc very well. Yes it is light weigh but that makes it easy to move and it breaks down very easy and that helps with moving it a long distance.
I have had mine for three years and it has no rust on it. A great buy.