There's no 'Property Stack' or 'Property Plugin' so you'll have to either use existing stacks or integrate a third party script from somewhere like PHPJabbers.
First though, can you give us a step by step of what it is your client wants visitors to be able to do when they go on the site?
- They go to a listing of properties
- Click on one and it opens in a new window
- They select this or that option
- Then the site calculates an annual rent (or whatever)
- They check out using this or that payment gateway
Without an understanding of the pathway, it's hard to recommend a way forward.