Hi,
I'll be pleased to work on this project for you. Let me introduce myself. I'm a CCIE certified network and systems specialist with 6+ years of experience in developing, configuring, troubleshooting and maintaining complex networks for large enterprises.
I'm passionate about Ubiquiti and have extensive hands-on experience with Unifi controller. I have designed and integrated captive portals with Unifi several times. I can easily fulfill your requirements. Please send me a message to discuss this further.