Deployment

I'm trying to configure my mesh to use both 2.4 and 5.8 nodes to communicate.
I have 
1 - hAP ac2
2 - hAP Lites
2.4ghz
1 - TP-Link CPE210
2 - Ubiquity M2-400
5.8ghz
2 - Ubiquity LAP-120
1 - TP-Link CPE-710
Switches
TP-Link SG-605
TP-Link SG108

Has anyone tried a mobile 900Mhz node deployment?

I have 2 Ubiquity LiteAP AC 5.8ghz 120 degree sector nodes up on my tower. One covering  NW sector and the other covering NE with a little overlap. I read in the docs that they should be on different channels to avoid traffic collisions. Is there a protocol for channel selection, or is it just whatever is available. I have selected 149 and 178 for now.