1kg may not be a lot to lift, but put gyroscopic effect into play and its a massive weight.
Rotas are far from lightweight.
Try Team Dynamics Pro Race 1.2, OZ Superleggeras, Desmond Regamasters are among the lightest you can get.
This may help: http://www.wheelweights.net/
All the wheels you have listed are only light in small sizes. At 18" etc most are heavier than oem rays and also lmgt4's
Not strictly true, the wheels listed above are the same in 18" variety, probably lighter if you could find Regamasters in 18 (very rare). Just giving the op some options of very similar weight 18" wheels if he doesnt like Rays.
Unless the op is a trackwhore then he's best just getting a set of wheels he thinks look nice and by a reputable manufacturer. He currently runs oem 18's and not rays so pretty much most wheels will be lighter.
Oh and he wants 19's