This should be enough to get you started
Sewell Lexus - F Sport stuff and OEM
http://is.sewellparts.com/#
VIP Auto Salon - JDM, Body Kits, everything else
http://vipautosalon.com/store/index.php/lexus/is-f-2008-present-use20-1
Carson Lexus - JDM, Joe Z stuff
http://www.l-tunedparts.com/index.php?id=140
Figs Engineering - Custome suspension stuff
http://shopfigs.com/v1/BRSERIESCOILOVERS
Digger08
Sewell Lexus - F Sport stuff and OEM
http://is.sewellparts.com/#
VIP Auto Salon - JDM, Body Kits, everything else
http://vipautosalon.com/store/index.php/lexus/is-f-2008-present-use20-1
Carson Lexus - JDM, Joe Z stuff
http://www.l-tunedparts.com/index.php?id=140
Figs Engineering - Custome suspension stuff
http://shopfigs.com/v1/BRSERIESCOILOVERS
Digger08