Online Payment Services website - credit cards and Bitcoin

Dear freelancer, We need to build an antire payment gateway website for cryptocurrencies where all users and merchants could get paid, deposit, exchange their coins to FIAT money on their wallet and request payouts to their bank accounts or to their bitcoin address. Payments method is only by credit card or bitcoin. However, nothing is going to be provided by us. You have to do it all, including an attractive desktop design and mobile version. PAYMENT FLOW: If coming from a merchant's website, customers will accept our T&C and an account will automatically be created when they click on PAY. If the order is paid by credit card, the payment will be PENDING on the merchant's receving account until our team accept it from the backoffice with our choosen exchange rate to BTC. ONBOARDING: If a user wants to become a merchant there will be an onboarding process requesting the KYC documents. DISPUTES: A customer should be able to open, escalate to admin and close disputes for any transactions made with merchants. ADMIN: Back office should have all the general settings available, such as deposit methods, withdrawal methods, transactions fees and text editor. As well as pending withdrawals, ongoing disputes, chargebacks, accounting, submitted documents by merchants. PLUGINS for merchant's websites: Magento 1&2, Woocommerce, Zencart, Opencart. API documentation. LANGUAGES: English, French, Spanish, Italian, German You do not have to make the translations yourself but all the texts on the frontend should be editable from our back office so we can edit them later. CODING: According to the project, we remind you that this website needs to be able to manage many transactions at the same time. Therefore, for security purpose and to keep good performances, PHP language is not recommended. MEAN stack would be best. Please list your real best price and timeline. We will not contact you to negociate as we believe the project is already clear enough to bid a good price. No upfront or early release, only 1 milestone payment. We will then release 100% milestone at the end of the project. We must see the website working before to release the money, atleast working on your server. You can then transfer it to our server after release, so it is safe for everyone. If possible, please show us past work refering to this project. Regards, For ADN Trading, Paris - France