I have the Mackie Onyx 1640 and 1620 (not the i-series) paired on my Linux DAW. They work great with Ardour and I have no complaints. But I’m looking to swap those out for a single unit of some kind. Does anyone have a 32-channel device, either a mixer or an interface, that you like (that works well with Ardour on Linux, of course)? If all I really care about is getting the audio into Ardour and don’t need any live manipulation of signals, would I be better off looking for an interface instead of a mid-format mixer? I know I’m the only one who can decide things like this, but I would appreciate opinions. 
Behringer X32 Rack with S16 for the other 16 channels has worked without issues with Ardour at our church. I think for a 32 channel it’s probably the best bang for buck interface.
The x32 rack looks really nice! I would prefer TLR ins, but I suppose I could get TLR to XLR cables.