How to connect 16 PAL cameras to one TX2?

Should I use some carrier board with two mini PCI-E slots to connect two frame grabbers(which boards? maybe Aetina ACE-N621) or use one mini PCI-E slot for frame grabber and a few PAL converters to CSI-2 (instead second frame grabber).
I want to use Sensoray Model 1012 frame grabber with 8 channels(link: http://www.sensoray.com/products/1012.htm)

Hi ArturK, seems the devices you plan to chose have no problem to TX2 from hardware viewpoint as they are standard IOs, so what’s the point your concern?