Fuel injector O-rings?


03 Protege5 / 90 Miata
Does any one have a good recommendation for fuel injector o-rings for our are cars? or will any brand basically do the job?
I have a pretty big gas leak to the point where all i smell is gas while driving. i know i also have an exhaust leak and the excess gas (if i'm running rich) could smell up the car, but while the engine is running I can CLEARLY hear a hissing sound from my C1 injector so I figured I would start there. But anyway, are here any good brands/ site I should be looking out for or brands I should stay away from?