I need a payment management system built into a website

General information for the website: We collect money on behalf of our clients and pay their agents / suppliers
Description of requirements/features: We collect money on behalf of various investments and remit the funds onwards to the agent, wholesaler, supplier etc. We remit different % and amounts for different companies and sometimes we will split a payment up to be paid to 4-5 companies.

There will be 2 distinct sides to the site – an agent login and our login (our login should have manager access and admin access, with different levels of access)

The agent side will:
- Allow an agent to login and enter details of a new trade (client name, address, dob, what has been purchased, amount due etc)
- From these details they will be able to click a button and produce an invoice with unique reference number to give to their client with details of how to make payment
- Agents will then have read only access to see the details of that trade through to completion, until I have paid the money to them
- The agent should be able to split the payment up to tell us how much to pay to their suppliers
- Agents should be able to see historic completed transactions and run monthly reports etc.
- Agents should be able to login from our website www.westcap-paymentsolutions.co.uk

From our side:
- The ability to create new agents and send login details
- Able to store agent details – their contact details, bank details etc
- Have a date stamped check list of actions through to completion (e.g. Funds received, AML complete, contract received, cheque cashed, cheque cleared, funds sent)
- Send an automatic email to agents when certain action have been checked off
- The ability to reconcile what has been received, what has been paid out, what should be in our account, what fees we are due etc
- Produce a completion invoice to send to agents and automatically emailed from the site - if payments are being sent to multiple parties, a master invoice and individual invoices
- Ability to upload client documents to share with the agents, e.g. Copies of passports, contracts etc
- Able to add adhoc items for payments i.e. When our funds have been claimed, when we have to deduct bank charges
- There should be master access for myself, and admin access (admin will have access to all the above, but not the backend of the data)
- Ability to set our fee for different agents at different levels, i.e. Some pay a flat £200, some are 2.5% with a minimum charge of £75
- Ability to add an introducer to the agent who will earn a split of the commission (this will be hidden from the agent)

I realise that this is a high level overview, if you could give me an idea of cost & timescale then I can go into more depth of the mechanics of it.

Thanks
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