I have no clue what the best back end would be for this ? We're also looking into a TMS/WMS/ERP application to host / offer to our clients.

I was thinking about Microsoft as their sharepoint, power automate and power apps would probably work fine with an application that might be written in dynamics365 / .net /... and that it would also offer long term integration and support with office365 accounts and plug ins to other apps.

Any advice on which flexible yet off the shelve set-ups there are out there for hosting such a web site and portal/web apps? I could go and contact some freelance consultants but I feel they'd sell us a solution we nitwits might not really need/want as a basis.