-Not too luxuary (fairly rugged/ordinary)
-Several beds, a few rooms.
-Barracks/Mansion looking
-Befitting for a gang of mercenaries
-A place where you can place all your companions (Got the Ultimate Follower Overhaul)
-At a fairly common place, not hidden ontop of the throat of the world, not hidden underwater; an ordinary home befitting for ordinary grunts. Inside one of the cities/towns would be best but countryside houses work as well.

I've looked through the Skyrim Nexus and the Workshop without finding something that really fit... If anyone knows of a mod befitting of this description I'd love you till the day we die.

Hmm, my home kind of fits the criteria (at least as far as enough beds for your UFO needs), but... Yeah, the rest doesn't really fit, with it being a re-purposed Dwarven hall, stacked to the brim with fun looking things.

Have you considered making your own? Houses are one of the easiest things to do in the Creation Kit, and I had quite a bit of fun making all of my houses.

For your followers' sake, just make sure you put in navmeshes.

You want my mod, if you are interested in a castle with a mansion and a LOT of barracks spaces. Clear out the bandits, and it's yours!! The prison (and barracks) have ample barracks, as does the a barracks in the base of a keep tower..

If you only want a house, this is not the one - but only you will know. You might end up making your own - but mine is perfect for a gang of mercs.

Lots of pix and a map of the location at both Nexus and Steam.

http://skyrim.nexusmods.com/mods/19481

http://steamcommunity.com/sharedfiles/filedetails/?id=99842710&tscn=1348956509