0w20 is not easily available for general retail; Mobil stopped making it a year ago (restarting it this summer) and Pennzoil just began to distribute it. So for now, get it from your dealer or NAPA has some in inventory. There's a post here that the Pennzoil can be ordered online now.
http://www.greenhybrid.com/discuss/p...light=pennzoil

Crush washers: this is the washer for the oilpan plug. Most mfg's use a gasket; Honda uses a metal washer. Can you re-use it? Sure. Should you? No- they're about 20 cents a pop from the dealer.

Filters are like Fords, Chevys, Presidential candidates, and NASCAR drivers- everyone loves one, hates the other, and gins up a host of reasons why their choice is the only correct one.
They all do the job reasonably well; nobody has ever pointed me to any evidence that one results in a higher failure rate vs another. If someone can gve me that info, I'd appreciate it. I have no doubt that a Bosch or some high-end filter does filter more and smaller particles for longer with lower pressure drop; its a matter of degree and what your tolerance is.