Thanks for the advice!
Approximately how much will it cost to get it lowered and how long does it usually take?
If you like the GTS wheels then get them and put them on the car and see how it looks to you. The Sv6 with FE2 suspension you have on your car sits a little lower than an Omega or Berlina and probably the Calais.
VEs all look better lowered between 1 to 2 inches from stock whether on 18,19 or 20 inch rims but you might be happy with how the car looks without changing to lower springs. It's your car and your money so if you are happy with it leave it as is. There are plenty of VE SS and SV6 running around on stock suspension and 20 inch wheels.
Set of 4 new lowered springs for the VE will be around the $280 mark (total) or more depending on the brand you go with (and where you buy) and you will need a 4 wheel alignment as well. Labour charges depend on where you go for the installation work. If your shock absorbers are worn you should replace them at the same time. Depending on how low you were to go, the fitting of a set of new shortened shocks compatible with the lowered springs may be required in any event. If you want some quotes then contact a couple of suspension specialists such as Wholesale Supension in Penrith or East coast Suspensions in Taren Point or one of the Pedders outlets in SYD.