You can easily make stereo In Ear mixes.. just use two auxes.
In smaller venues the FOH guy IS the monitor guy - so that's something to bear in mind. If you're playing venues which have a monitor desk, then it's probably about time to find a guy who can run monitors for you.
Obviously you can run a split system - and one of the band can control the in ears. This way you'll need to purchase a splitter (rack unit ones like.. T-Racks from thomann, 8 to 16 xlr - £130 or physical box splitters [more difficult to implement when touring unless in-line]).
When doing monitors you don't need ALL the channels through your ears - that just eats up headroom and doesn't really need to be there. For instance, hardly any drummer I know has their individual toms, just overheads. They also won't use both kick mics - just one. Guitars are the same when multimic'd.
So - a typical band will probably only need 8-15 channels of monitors - which is 2U of splitters.
A small desk with 4-6 Auxes (as headcrusher said, post-fader) is easy to rack mount and stick your splitters underneath.
If you want, drop me a PM and I can help put together something for those that are interested.
[edit - headcrusher... Monitors is the only thing that LS9's are good for !

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