Always use the OEM oil filters. They have the proper by-pass flow rates & can be had cheap enough (I pay about $4 each for them & even full price at the dealer shold be no more than $10)
Use standard Honda GN4 until about 2000 miles then switch to a full synthetic if you want to. I usually wait til my dealership has an open house or something & offers them up for like $1.50 per quart & buy a case or two to keep on hand.
If/when you go to a full synthetic I have got to say that while I normally do not get involved in oil threads (I find them very closely related to politics & religion) I have been on the Repsol Oil band wagon lately because I have not found any FULL SYNTHETIC oil that works better! I've tested most of the current top brands & this stuff really works. You don't notice any more hp or anything like that, but the transmission & clutch action is sooo much smoother than anything else I have tried & it never slips even on my HRC kitted superbike motor.