Which solution should I go for?

Hi

I have been assigned the task to create a SharePoint Online based “Systems Catalogue” which will contain a lot of lists that are related to each other (eg. Systems, Servers, Costumers, Roles, IP-adresses etc).

As I see it, I have three possible ways to do this:

1. Pure SharePoint
2. Access Web App
3. BCS

Some of the main issues with these three solutions are:

• Pure SharePoint will give me a lot problems regarding relations between lists.
• Access Web App doesn’t support many-to-many relations.
• BCS doesn’t support workflows.

So I am having a hard time deciding which solution to choose – or if I should advice against SharePoint all together.

I need some advice. Which solution would be best seen from the users point of view and which would be the easiest to maintain.

Thanks
Jakob