Appointments + (+ other add-on services)

Hey guys,

I got the appointment plugin working and configured and I understand the flow of how to use it with Marketpress... (Great plugin!)

So my questions is this, how would I create an "Appointment Product Page" which I can then add services to?

So here's a scenario...
A hairdresser, offers;
1) Wash & Trim :wink:
2) Wash & Cut
3) Wash, cut & color (dye)

And with that she has a suite of other add-on products... Example;
1) Deep conditioning
2) Facial waxing
3) etc...

So the goal is to have the client select a package and then have the option to add-on extra services. So we thought about several different ways of doing this, but each seem to have there own set of issues. Such as for example...

If we just create the addon as regular products that will be great and dandy the "Appointment Product" package selection and the addons will show up in the cart. The issue is how do we take the extra time into consideration??? Example someone selects Package #1 (Wash & Trim) and selects the addon of facial waxing. If facial waxing is only handled as a product it will not take into consideration any extra time this may add to the Appointment. So the question is how would we create an appointment (package) which we then can have the option to add extra services to. Hope I'm explaining myself properly and asking my question clearly.

Our other thought is that CustomPress would be needed, but we're not sure where to start. We wanted to reach out and get your direction on how to achieve this, before just jumping out there.

Thanks in advance for your help with this.
Best!