Dustin,
I feel that the MM's oil life prediction is fairly accurate (this, from 150K miles of experience on our Fit).
Oil recommendations for Hondas are not as stringent as some Euro makes. (They don't specify a 'specification' number) So any oil of the weight mentioned on the filler cap should be OK.
Oil recommendations vary dependent on your locale, and the type/weight varies by model. Tell us what you own! Put it into a SIGNATURE when you get 5 posts. <img src="http://www.crvownersclub.com/forums/images/smilies/redface.png" border="0" alt="" title="Embarrassment" class="inlineimg" />
Regards a filter, if you DIY, the 6-packs of factory filters from online dealers are very cost-effective. If you prefer to buy at a retail outlet, don't get the cheapest, and don't waste your money on an expensive boutique brand, either.