Advanced website build

General information for the website: Equipment rental company
Kind of development: New website from scratch
Description of every page/module: The website is specialist for companies who have lots of equipment they need to rent out and they too are likely to be renting out from other companies as they're all in the same industry and it's quite specialist.

They will be searching for products which are available to rent in a specific time frame and will be checking the availability using a calendar feature. Then they will be requesting a quote which will go out to all the vendors who have stated that they have that equipment during that time.

Budgetwise, I have no idea how much this will cost so open to peoples suggestions and proposals.
Description of requirements/features: Step 1
The user signs up and has to pay X amount to join. Initially a coupon will be given to waive that fee (Membership plugin)

Step 2
Vendors and users (people who will rent) will have the same rights. If they want to rent out their equipment, they will choose the product themselves from a library/database of pre uploaded items from the admin. Each vendor will input the dates they have the equipment available on their dashboard into a calendar style thing.

The person who is looking to rent the item on a certain day will select the item from the search drop down, use the calendar to select the dates they need it for and "request a quote". The quote request will go out to all the vendors who have the item during that time only. The vendor inputs a quote, the user gets emailed or can see the prices in their dashboard and accept of reject.

Ideally when the user has accepted the quote, they will pay a commission for using the website which will then reveal the vendors details and they can talk in private.

I am a web developer as well, so happy to accept quotes for the whole project or just plugin customisation only part and I do the design and other "easier" parts of the website. I know there are loads of plugins out there but can't find any to the exact T so guessing its a customisation job.

Or if you have another solution then outline that and the proposed costs.

Thanks
Extra services needed: Customization
Extra notes: PLEASE NOTE: Every time I put up a job on here I get many Skype requests and phone calls which I really really don't like. I prefer being able to sit down in my own time and read them when I can and ask/answer any questions. If you try to ring me or message me on Skype you are going to leave an instant negative impression on me because I know you haven't read this.