A320 Rating
Try North West Airlines in the US. they will do it for USD12,500 the CD's will be posted to you before the course for self study. If you have trouble getting their number, you could get it through Eagle Jet in Florida.
The B737 Rating is a lot cheaper its done on the -300 but the rating covers all variants.
In the past CASA would accept the training and endorse your licence. However you would need that in writing beforehand in case something changes midstream.