Event Registration using webform and commerce

Hello all, I have just spent the last three days going round in circles with this one and would love the communities input.

What I have:

A D7 website providing informational content and a webform for a Laser Tag business operating from two separate locations on different days. Location A runs on Saturdays and Location B on Sundays. Session times for private groups are in two hour blocks and a there is one Public session per day allowing multiple individuals. On top of this there are also special events now and then like tournaments.

What im trying to create:

A Booking system that displays availability of sessions to the customer via Calendar view for each of these locations. They can click the date they require and select the session slot if available. Here they will be presented with a webform prefilling the session they chose and gathering all other information we need. The session itself and any other options can be chosen here and added to the commerce cart to be purchased after the webform is sent. The registration for this selected session will remain as pending until payment is made.

The modules im trying to use for this:

webform
commerce
views
calendar
date
entity registration
commerce registration

Where im at now:

I had trouble with displaying availability and started looking for other modules that package that type of functionality, the problem being I always needed to come back to commerce registration and the entity registration modules to make them payable and pending. I've looked at so many options now that my head is in a whirl and im wondering if someone out there could help get me back on track.

Thank you
Mako