I'm always here ;) hehe
A web block, in this case, would be nice because you would be able to do everything inside it, but would require notifies to the page.
Talked to your colleague about it, but I really think they don't like web blocks in there...
The local lists are also a valid possibility, reducing database access and the logic is very simple. But if the number of records is too high probably would not be a good approach...
Good luck!