php m a s s real estate modifications

I need a modification on my real estate site based on p h p m a s s script. I need a availability calendar of rentals and it has to be simple to install cause i need it on 4 site's. It have to work with the admin panel of the script so when i insert a properti for rent calendar comes up and i can select wich date are availabie. Also i need a multi language for my sites english , italian , german and french mabe with litlle flags on the frontpage.