If you need 5 projectors, it might be complicated with a single laptop. You would need a Matrox triple head and a dual head. Drivers of those things are sometimes a headache. Also if you want full HD outputs, doing 5 fullHD on a MacBook is maybe overkill. On my mid-2013 I did tests with 2 zotacs (MiniDP->2 HDMI, out of order...) and could have 4x1920x1080 outputs and run 8 full HD movies on all of them. But I don't know if I would do it in a critical environment...
So for this setup I would use a Mac Pro with 6 active MiniDP-HDMI adapters. I use the Startech ones and had no issue with it:
https://www.amazon.fr/StarTech-com-Adap ... ni+dp+hdmi