Ubercart Customization

I am working on a project for a client that requires some custom development. The site offers members the ability to sell time slots. Presently I have set up two content types 1) Location and 2) Product (time-slot). The time slot content type only allows for one time slot to be entered at a time either 1 hour or 1.5 hour increments and references the location content type. This is very annoying for the seller because if they have 6 hours to sell, they have to create 6 product listings. Ideally, I would like an interface developed that allows the user to create all listings from one screen.

1) They should be able to select the total time available for example: 12:00pm to 3:00pm
2) They should select their increment for example: 1 hour, 1.5 hours
3) Timeslots should be created for each available increment. For example if they select 1.5 hours, two time slots should be created that can be purchased which would be: 12:00 to 1:30pm and 1:30pm to 3:00pm

I need someone with lots of ubercart experience who can provide the ideal or better solution from what I have available at this point. This is a tight deadline, therefore I need someone who knows what they're doing and can get it done quickly. Please send me your suggestions. I can forward you the current site link to review if it will help.