you would better specify the nature of tasks and projects of that shop... I assume you are talking about Software development?
Then I would highly recommend MS Project Server...
1. Each project - is best to handle in (most used) MS Project , using the SAME template (we have modified standard MS SW Dev waterfall Template and used it over 7 years for more than 500 projects)
2. MS Project Server will allow you to handle "Project Portfolio":
* Project/Tasks priority
* People assignments -> best people time utilization
* it is easy to add "time registration" (T&M Invoices to your customers)
* and build better estimations for new projects on top of existent portfolio and history time data
MS Project is not very good suitable for Agile/Scrum (Better Jira/ Trello), but project portfolio is still good.