ESP8266 WiFi based simple WWW server with UART data acquisition. Preferable NodeMCU based.

Hardware platform: ESP8266EX with external 128mbit flash 25Q128F Winbond chip for program and data storage. Preferably based of some commonly available ready-made module PCB for start, transferable to our own ESP8266EX PCB solution later. Software platform: NodeMCU preferred (or other open IDE/SDK) but we are open for any reasonable suggestions that do the job, including paid/licensed commercial solutions. The restriction is that we have to be able to correct/modify the code later, compile and upload the firmware by our owns. Goal: ESP8266EX has to accept asynchronous ASCII data transmission on UART0 port (fixed, standard baud rate up to ~1Mbps) and store the data in TXT file created in the external flash (25Q128FV), then present the data in text form on built-in WWW page. The UART transmission should be accepted only after receiving a specific UART command like:"START123456" carrying password to prevent data accept from unauthorised sources (other method suggestion welcomed). Preferably the entire Flash memory content should be protected to avoid reverse engineering or compiled firmware copying. Beside of above the rest of requirements are quite regular as for ESP8266EX based system: 1) ESP8266EX needs to run the WWW server in the parallel task, offering simple HTML-based WWW page with ASCII text area preview of the stored data as well as downloading the data in the form of TXT file. Display/download data range has to be selectable (in form of size in bytes or fixed size memory pages like 512Bytes per page - if more convenient and easier). Display/download option needs to be updated dynamically (with some reasonable period like 5s) by new stored data. Page example in the [login to view URL], image002.jpg. 2) All WiFi/network configuration should be available through WWW sub pages (WiFi mode change (AP mode, client mode, SSID name, hidden SSID enable, channel, security mode selection and password, IP, GATE, MASK settings or DHCP server enable). Page example in the [login to view URL] 3) ESP8266EX has to support two selectable working modes: default AP mode (it serves the WiFi network) and wifi client mode (ESP8266EX is able to connect other network). In both models DHCP should be an default option (server for AP mode, client for device mode), but manual IP assigning should be also possible through configuration WWW pages. In every WiFi mode selected (AP or client), same set of WWW pages needs to be served allowing text view/download and ESP8266EX reconfiguration. 4) ESP8266EX has to initially work in pre set AP open network mode, with fixed SSID like AiR12345 and fixed base IP like [login to view URL] 5) Asynchronous UART data recording to TXT file has highest priority, always, data drop rate is not acceptable. 6) Remote FTP server data backup (txt file) and e-mail data report (with TXT file as attachment) considered as an extended nice-to-have features. This is the scope of basic starter project only. Advanced options may be discussed/developed later but have to be considered at the beginning, depending on work status and results already achieved. This may be the long term cooperation based on small project updates according our needs. Please let me know if you are interested and provide your offer/quotation and estimated lead time. Detailed questions are welcomed.