Thanks for all your help guys !

I finally bought these coils : http://www.ft86speedfactory.com/st-s...t-ta-1645.html

They seems really HQ and I was able to get them brand new for, believe it or not, $1,103 USD
shipped and taxed !

I'm glad I actually made some phone calls. I'm not gonna name the seller as it was his last one and requested me to not name him.