The third slice is a twist of the NanoBSD script that needs to be enabled in order for the script not to crash and burn. It's not used.
Are there any hardware recommendations from the projects side?
...I'm just a user of the OPNsense project, so I can't give an "official" recommendation, but I'm running OPNsense on the following boards:http://www.supermicro.com.tw/products/motherboard/Atom/X10/A1SRi-2558F.cfm...The C2558 does provide AES hardware encryption while the J1900 does not, but it has a lower price point....Regards- Frank