Jim,
The way I built my band's IEM rig, we can use it when I am supplying PA, or if we use the house PA. Here is a quick rundown of how ours works, it may be helpful to you:
Our wireless IEMs (and headphone amp for the hardwired ones) live in one rack onstage, along with a small monitor console (a crest XRM20). We mix our own ears, but typically we need very few if any adjustments after sound check.
The rack has an input panel on back with 5 whirlwind W1 multi pins; three are inputs, two are output. We drop three of our own stage boxes, patched into the W1 inputs. This means we never mis-patch a snake to the desk, and patching the 5 snakes takes less than a minute. Our boxes are all clearly labeled so the crew in the venue doesn't screw up either. These inputs feed the desk which has its own split. I have an input on one box for talkback from FOH.
The output W1s are wired from the split, for 2 sets of 50' tails terminating in male XLR. After around 75 gigs on this rig in the last year plus, that has proven to be the right length for about any venue we play.
There have been many advantages for us using this system. Probably the biggest are decreased set up time, and more consistency in monitor sound. Our rig sets up in under 1/2 hour including patching most every mic and DI (a few we patch ourselves). For sound check, we are all typically good to go after 1-2 songs. Mind you, this is for a 14 piece band. Prior to this, we would expect to show up to find 6-10 mixes onstage and a set up/sound check lasting 1-2 hours if the monitor engineer was good; after all of that it would typically sound mediocre onstage and we were stuck staying in our mix zone.
I know I am not specifically addressing your questions, but hopefully this gives you some food for thought about how you might build it. It would definitely be to your advantage to make it work easily when using a venue's PA or your own.
Cheers,
Nils
