hmmmmm..... is that really so great having 2 mics right next to each other?
i do like the boom arm idea though, makes it all adjustable. is it all screwed in under that white cover?
as for shock absorbtion, are that many vibrations really gunna make it out my kit, up the walls and onto the ceiling?!?
I don't think you need to worry about vibrations going through the ceiling and affecting the ceiling mics. Floor stands are subject to the same vibrations and no one thinks twice about that. In fact, floor stands are subject to footsteps, etc., and ceiling stands are not. I've never noticed a problem with my ceiling-mounted mics. Most mics nowdays have some internal dampening anyway.
It is common to mount two mics close like that but you will usually want to point them in opposite directions. Or, you can put one of the mics in a floor stand and leave the other in the ceiling stand. I have done it both ways.
Under the white cover (which is just a tabletop mic stand painted and drilled and with nylon grommets to not abrade the cord) is a hole in the ceiling and the cables run up into the hole, inside the ceiling, down the wall and through the grommeted metal plate to plug into the mixer. I did this in conjunction with the ceiling fan installation that helped make it easier.
I bored holes through the stand and screwed it to a ceiling joist. I countersunk the holes and painted the screws, so the screws are not easy to see and the installation looks cleaner. There is about four feet of cord stowed in the ceiling that I can pull our or push in as needed.
Between the boom and the base is a section of 3/8" rod, threaded at each end. I have more of this rod and connecting bolts on hand to extend the boom downward even more if needed.
I would encourage you to go the route of drilling a tabletop stand into the ceiling and using a boom stand. With extensions, I can drop the boom to the floor for recording tablas, or move it in a wide arc to pick up bandmates. It has plenty of versatility.