Every project guide page should have an easy one click parts to buy list.
The current part lists are incomplete and are simply links to the product listings.
For example, aren't they 2 types of O-rings needed per injector ?
Porsche 911 Injector, O-rings and Sleeve Replacement | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article
http://forums.pelicanparts.com/newreply.php?do=newreply&p=6525279
It's also OK to include more items than absolutely necessary. I don't mind pruning a buy list of items I already have.