The real estate script will have to have a special capability, that multiple "store fronts" can be used, but they share the same property database:
Based on the web address the front end is accessed from, it should display a different header. For example if you go to xyz..com it will show xyz's logo, name, etc.. , if you go to [url removed, login to view] it will show abc's logo, etc...
But the property will share the same database.
With your bid, explain if you are going to be using a ready made script to base things off of and if yes, which, script.
Also explain what tech your are planning on using.
Without this information, your bid wont even be looked at.