Hey Brett,
If you are interested in a home made version of a Group A Manifold have a look at this Street Commodore thread:
http://forum.streetcommodores.com.au/showthread.php?t=8505914&page=3My son has had a go at making his own verson for his VQ Stato.... certainly cheaper than market prices.... may even be an intersting read for his whole post.
BTW, you met him about 18 months ago whem I bought some master cylinders off you - he was more interested about your son's Commodore than your FC... even though you have the Commo rear end.
Regards,
Trevor_B