Custom design web system and Mobile App

Hi y’all,
I’m looking for a team that could help me with a design of brand new customised website and a Mobile APP, it’s for a corporation that does a lot of events that have to be LIVE STREAMED for the international visitors. and work with tones of graphical material, and videos.

That mean plenty of activities and communication tools, and interactive possibilities.
Member sign up possible on the Mobile APP as well as free usability options, on the website possibility for payments processing system and donation processing system.
Possibility to collaborate with CRM systems for events or administration use (SALESFORCE or others), interactive for live events.

So a brand new system that is user friendly, with abilities to extend and collaborate with other platforms or applications necessary.

I need to know the price of something like that, and all the information that I would need to get something like this done plus time it can take to be ready.
Because I will need to present this information to my clients, so all information that you can provide in details including design sketch that I can use during the presentation will be great.

I came to you because I have worked with you in the past and loved the collaboration, and your system that I’m still using now. I just love it, and I now hope together we can work to create something price effective and brilliant for my clients.

Look forward to your reply,
Glory Isunga