Used OEM ones will be your best best for the street. They will fit 100% correct 100% of the time. If/when you need to replace them, you know that any other OEM piece will fit 100% like the one you are replacing. You can also buy some QUALITY fiberglass race plastics from a reputable company and mold in a headlight if you are good with fiberglass. Sharkskins, Attack, and hotbodies are good brands. There are probably a couple that I am forgetting.
Be prepared to do some work with any plastics that you buy that aren't oem. You are also risking getting junk that doesn't fit right and will sit too close to the exhaust and melt. It's either pay now or pay later. There is no getting around it.
All of the chinese stuff on ebay is crap. It's crap painted to look really nice and shiny. If you spend much time over there, you will see that it is very common to put nice shiny paint on junk and try to sell it to stupid Americans. They have truly proven that you can polish a turd, they just painted it first.