I know eBay is a popular whipping boy for some, but after a few hundred parts-buying experiences, I always look there. These are usually little guys like me and most of them work their ass off, ship same day, etc. And there are plenty of new parts there.
By contrast, ordering from folks like Partzilla I have never received anything faster than 10 days. Not once.
But the BEST is my local Honda dealer, for Honda parts. I email them a complete list and if I need it fast, I say so, and pay the $10 expedite fee Honda charges them, and I have it 2 days later, max. It is definitely worth having a relationship with your local if you can make it work.