Welcome to the forums, you'll have an 'easier' time finding wheels to fit a Probe as opposed to a Cougar as you have a much more common stud pattern. Depending on the look you're after there is a wide variety of different rims you can get.
Take a look at
www.directwheels.com.au , they have a Probe on their site here
http://www.directwheels.com.au/compo...id,8/PageNo,1/
or try
www.tyres.com for a huge range in wheel choice.
Dan