Connecting Fortigate FW with HP 5700 in Two Tier design

[Capricorn800]

Hi!

I have two tier design with two 5700 in IRF mode connecting to 4 switches for servers and 6 switches for Access layer. Its kind of leaf with all 10 switches are connected to 5700.

Now I have to attached Fortigate FW to our network. I beleive the best place will be to connect it with one of the Server switch and make it trunk.

The FW will contains DMZ network and will serve internet. I have SVI on 5700. 

Any possible guide for this as I dont find much of the documentation about HPE networking or may be I started fresh with HPE and I dont know the right place to look.

Please suggest me about the best option of connecting the Firewall with HPE and Aruba Access layer switches and also links to find design guides for HPE 5700.

Thanks