Gentoo on cubieboard2 (all winner a20)

Okay so I want my cubieboard to be setup so I can plug sata drives in for repair, so using clamav for virus removal etc etc, now I haven't got a clue on installing Gentoo on arm or x86-64 so any advice is well come, reason I want gentoo is because or compiling and the fact I can make it super minimal and mission based (repair) so is there any idea on how to do this or any guides? 

Thanks 

x86/x86_64 installation guide - https://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1

arm installation guide - https://www.gentoo.org/doc/en/handbook/handbook-arm.xml?full=1