From a redundancy standpoint, two separate 8612s would be preferable
At retail 8612 is $3,600 and an 8612xsv is $4,100 = $7,700
A 9219 is $10,000 plus say a GCV 20 sonar plus transducer at $630
The 9219 costs say $3,000 more, and while only one screen, the 4K subdivides very well into 2 to 6...