Aldus Voice’s website was my primary guide:
https://aldousvoice.com/2014/03/25/ferrari-f430-exhaust-manifold-change/

Here’s all the various parts I purchased:
Phoenix Headers: https://phoenixexhaust.co.uk/products/ferrari-f430-series-stainless-steel-sports-manifolds-headers
Studs (16): https://www.ricambiamerica.com/211641-stud.html
Header nuts (16): https://www.ricambiamerica.com/210971-nut.html
Gaskets (2): https://www.ricambiamerica.com/211404-gasket.html
Collector Bolts (6): https://www.boltdepot.com/Product-Details.aspx?product=5822
Collector nuts (6): https://www.boltdepot.com/Product-Details.aspx?product=17708