Old/New property, gst and stamp duty

Hi, I'm new to this site and property investment so please take it easy on me!

I am looking at a property that the vendor has built over about a 20 year period and is still incomplete. It needs a kitchen and floor coverings, some plumbing and painting.

will I be eligible to claim gst on this property? And is is stamp duty calculated like any other property in Vic for this ?

I would be purchasing it through a company(gst registered) and using it as a holiday rental property.

Any help would be appreciated.

cheers