KYB's will work...I think they are the most affordable shocks for our cars out there...I really wish the shocks fitment from the G35's fit our cars....they have more aftermarket shocks choices
when my OEM sport shocks were going bad, I replaced them with the KYB (non-sport) at first and I also had the H-techs, then shortly after I swapped them out for the KYB sports (Excel-G). My wheel/tire guy had the KYB rep at that time come in and bring the sport shocks to try on an M, so I got the call
I created a post some time ago - here's the link:
what-the-f-front-shocks-t527102.html
so far so good...I could tell the difference from the KYB non-sport vs sport. both good, but I like the stiffer feel from the sports. I still have my H-techs and have been going back and forth between getting the Eibachs or coils....
Here's a link that has both sport / non-sport
http://www.carid.com/2006-infiniti-m45- ... 62258.html