Bespoke Affiliate Scheme creation with Wordpress integration

We are looking to code our own affiliate scheme using the following steps.

We have a Wordpress website which this would need to work with.

1. Affiliates register on our website and get their own URL to promote
2. We have database of registered affiliates and their IDs
3. When a customer visits the website through the affiliate link it follows their actions and if they fill in any of the lead forms on the website is will add a hidden field to the form with the affiliates ID
4. The system will need to count the number of leads they have created and display this in the affiliates own login area and in our own admin area.
5. If a sale is made, our system will check if there is a referer code in place. If there is it will use Zapier to send a Zap to the new system registering a sale for the user.
6. The system will notify the referer they have a sale and mark it down in the database
7. We can see all referers and the sales they have made
8. Every time a sale is made we will pay commission instantly
9. The Referer can also give their link to other customers to sign up for the referral scheme. If somebody signs up using their link and they sell something then that person will get their commission and we will also give the original referer a small commission for this too. We need this incorporated into the system so we can see the parties that have been referred to be affiliates also and the commission added here too.
10. We will need a nice back-end area in Wordpress to show all of the affiliates, their leads, their referrals and commission they have earned.
11. The affiliates will have a login area which will also give them access to their information, leads and commission.

We are looking to start this as quickly as possible so please let me know costs and timescales in your quote