O2 extenders????

[mark Rosokoff]

I just recieved kooks L.T. headers;hi-flo cats;and X-pipe and was wondering how many O2 extenders will I need for install,,,two or four???also should I get locking header bolts,or just use the same bolts (stock)???Should I look into Jet Hot coating?? to help keep interior temp down??? The headers look like plain tubeing with T-304 written up and down them!!!