Availability calendar development for Geocore 7.0.3 script from Geodesicsolutions.com.

I am looking to have a simple Availability calendar developed for the Geocore 7.0.3 script from Geodesicsolutions.com. The website will be predominantly used for accommodation and travel. The Availability calendar would need to be developed for the classifieds side of the script. I would be looking for the following to be included: 1.) Property owners should be able to highlight the vacancies for their establishment when they place a listing/classifieds through the site. 2.) It would be great, if the calendar would be independent of updates of Geocore. For the time being, I am looking for a simple availability calendar to be included. I am looking to further develop the features of the calendar in the not too distant future.