Hello Stelan,
depends on car and model year. Don't check online shops for part numbers. Use the Porsche 986 parts catalog:
http://www.porsche.com/all/media/pdf/originalparts/usa/986_USA_KATALOG.pdf
Download the pdf, open it on you computer with Acrobat reader and there you have the option to use table of contents in the document.
Metal flange inner side: i don't know if i understand the question correctly, but the cv boots are clamped on the axle side and on the outer flanges side. Recommend an Oetiker plier to put the clamps on.
Regards, Markus