Build a Thumb-tack concept style website

Need a website to operate very similar to concept of Thumb-tack based on one industry making up numerous job categories. Users will post non-public jobs based on webform answers which then gets emailed out to suppliers who will bid and provide comments (suppliers will not see other supplier bids). Must have a user and supplier within signup/login and admin panel for which separates jobs requested. Suppliers will be matched with job categories and also option to limit to locality. Suppliers matching criteria will be emailed notification of job details from form build in pdf attachment and requested to login to provide bid. Payment portal (paypal) will be on acceptance of bid calculated on % of bid. Back end admin must provide full control with excellent functionality to review and monitor jobs and bids, user and supplier information and statistics etc. Must be able to turn on/turn off preview of jobs, bids and communication to stop spamming etc. Also require option to run everything through keyword script to flag certain words to detect spam etc to reduce manual review of every job. After job complete, ability to provide star rating as well as comments (subject to admin approval before publishing). Will also require time limits to be implemented for each stage. I would preferably like this to run through WP as I'm most familiar with this, but acknowledge this may not be the best framework solution. To be successful, you will need to: 1. Explain how you will complete the job (more detail is better); 2. Timeframe (less is better); 3. Price (must be competitive). Simply saying you can complete the job without explaining how, will not get you the job. I want to be able to assess you against other freelancers in providing the best solution. I've already become acquainted with the clone scripts that are available and not looking for you to just sell me one of these and installing on host. I will provide you with a theme style example by which to do the front end. I will not release money upfront, you will be paid for work completed and which I receive and all coding becomes my property on payment. I also expect time frames to be kept, if you can't meet your own deadlines, you shouldn't bid. If you are confident in your ability to supply a professional bug-free product on time, you will not have a problem with this. If you can do this, I have 2 other websites waiting to be developed as well as ongoing upgrade/additional features requests and you will be the preferred supplier for the work.