um, think this has been covered. Try searching first, that will save you much headache I think.
I am personaly runnig felpro with no problems and I boost from 10-16 psi and I beat the hell out of my l28et when i do drive it so i think felpro is fine, most will say that your tune has the most to do with how long your headhasket will last. if i have to do it again it will be OE Nissan though.
took just a second to find this
http://forums.hybridz.org/showthread.php?t=115904
http://forums.hybridz.org/showthread.php?t=106698
http://forums.hybridz.org/showthread.php?t=97828