Easiest way to live record from 2 separate audio interfaces?

[eljay1]

My buddies and I have jam sessions where we have 2 separate audio interfaces going separately and the 2 people running the interfaces have separate computers (1 Windows / 1 Mac) and each run Ableton and have control of our own audio signal, and currently we route the audio through a synth (Roland Fantom, which has spare input channels), then out to studio monitors. It works great to jam live, but we are trying to figure out the best way to record live and it would be nice to still maintain all of the separate channels for mixing if possible.

We have a fair amount of gear including a Behringer UMC1820 interface which has plenty of input / output channels, as well as ADAT and SPDIF in/out, but we have never used the ADAT / SPDIF connections. We also have a spare laptop to record to if needed. It doesn't need to be pro level recording or anything, but it's a bit overwhelming to figure out the best and simplest way to set this up. Any input or recommendations would be greatly appreciated. Thanks!