Deposits

I am using OpenResort on a project and would like to know if it is possible to only accept a deposit for each reservation and then allow the user to login and pay the balance at a later date. Is this possible out of the box with the e-commerce modules? If this is not possible out of the box is this something I can achieve by writing a module or is this not possible with the current set of modules. I am using Paypal at the moment but might want to include another later.

I only ask here instead the OpenResort issue because I think this is more related to the core e-commerce than OpenResort.

Thanks for any help.