I'd like to record my scenes with two computers - one with 6 PS Eye cameras and the other - with 6 PS Eye cameras too. It wood be great if I could combine this two records for calculation purposes in IpiSoft Studio, so that I could use for tracking records from not 6 but 12 PS Eye Cameras.

Why do you need to do tracking from 12 cameras? It does not add any accuracy, just more de-synchronization issues. If you definitely want to try tracking with more than 6 cameras, start with 8 connected to a single PC. You can use 4-port USB 3.0 card to connect 3-4 PS Eyes. iPi Mocap Studio currently supports tracking for 8 cameras as experimental feature.