You should get in touch with the dealership in the city that you are heading to.
http://www.westforever.fr/opencms/openc ... aires.html
They should be able to help you arrange the inspection and re-registration. Any non stock items such as braided cables etc. need to be removed and replaced with stck etc. they are quite strict. There are also some rulings on the number of years you have been the private owner etc. for GST and tax exemptions.
When I have checked out the price of used Harleys in Australia I have found them favourable to Singapore even after adjusting for exchange, probably due to the larger market there. You should check out the local pricing with some of the dealers whilst you have them in the line (or check out some private ads).
One of the Harleys I purchased here was from a fellow Australian that found he was better off selling his Ride locally and buying another when he got there after taking into consideration the payment to the dealership here for preparation for export, export and freight charges and payment to the Australian dealership for unpacking, prepartion for inspection and registration etc.. On the other hand if the company is paying your relocation then why not - no two rides are the same right.