Have been running Pennzoil 5W-20 in our 02 Accord V6, now at 63 K miles. UOAs are excellent (also use LC an a little 132). In the northern NE climate, cold winters and moderate summers, you should be fine with any of the good 5W-20s, dino or synthetic. We were just up in western Mass. over the weekend, got down to 2 degrees F.
I use the Honda OEM PCX-004 oil filter, made in Japan by Toyo Roki, specced for the S2000. Believed to be a better filter than the other Honda OEMs.