Welcome to the forum.
Those parts are very common faults on these cars. For new parts, I always like to check Pelican first; good prices, customer service, and they are the forum sponsor. A local dealership can also be good for plastic trim, nuts and bolts.
If I need any used parts, I first check with Woody:
http://986forum.com/forums/boxster-parts-sale-wanted/52469-parting-out-whole-lot-boxsters.html
(user name
itsnotanova)
If Woody doesn't have it, I'll go to:
Quality Porsche Parts | eBay Stores
Short of having a parts car, that should cover anything you'll need.