Investigate and analyze criptocurrency development libraries

Hello freelancers, Me and my team are developing a p2p bitcoin, ethereum, dash, etc Exchange. So we need an expert that can find libraries that we should use in our site to build bitcoin and other crypto transaction. How our site works? Is going to be using ads (example: [login to view URL]) but we are going to use differents cryptos. User can charge funds into their account in the site and then sell it into FIAT local currency. So we need to develop that system where users will post their ads and users can buy-sell crypto with a fixed price. We need to take a comission when users deposit-sell in the site, so we need a main wallet where all comissions are stored. Create new wallets where users can deposit, i hope you understand the idea of the site so we can discuss more about this on chat. Maybe one of the library we can use there is this [login to view URL] Freelancer should send us a detailed document showing and explaning wich library we should use including detailed functions that we require to develop this system. Thank you!