FortiGate 100E

[tomugh]

Hey everyone, I got a FortiGate 100E model. I need to install it to setup an access to security cameras through the Fortigate 100E by using a smartphone, a tablet or a laptop. I would like to know which way is the better one to get the fastest authentification as possible and the most secure one using three main features : VPN + Certificate + Tocken. 

I explain myself : First, a VPN tunnel totally secured between the legitimate device and the firewall to be able to access video camera (the FortiGate 100E can do that, no Radius and AD needed). Then, I need multiple authentification :

First of all, verification of the legitimate device's identity (I thought a certificate exchange between the legitimate device and the firewall ?). After that, to enhance authentification security level, verification of access rights (login and password), maybe with VPN IPsec ou VPN SSL with a double-authentification by Token ? Or simply VPN SSL with certificate exchange then a three way by using FortiToken mobile or laptop ? I've seen after the certificate exchange, we can use FortiClient to establish a connection between the legitimate device and the firewall; One more thing, I know that a vulnerability scan is possible. But is it fast enough for a quick connection because I need to access security cameras as fast as I can.  

So many questions... 

Thank you in advance & have a good day