New to Doubles

[Chris H]

You are on the right track.
I assume you have a backplate and an appropriate wing to go with your new doubles?  If not, stop right there and get a Backplate and a wing specifically made for doubles.  I have a Halcyon Evolve.  A 60lb for bigger tanks, and an 40lb for smaller doubles.  I wear the 60 with 130's and 95's and the 40 with 80's and 50's.  Dive Rite also makes good wings.  I do prefer the donut shaped wing to the horse shoe shape, but YMMV.  I have SS plates from Halcyon and Dive Rite.  Either are fine, and there are many brands out there that will work.  SPG on a 24" hose and Backup regulator on the left side and a long hose (7ft) and inflater hose on the right side.  I use a separate inflation system for my drysuit which isn't necessary unless you have some helium in your doubles.  I assume if you are considering deco diving around here you also have a drysuit.  Put the drysuit inflater hose on the left post until you get an alternate inflation system.  On inflater on either side will give you back up inflation if you have a reg failure.
  has some good information.  If DIR isn't your thing, do a search for Hogarthian, and you'll see similar configurations.    Keep it simple and clutter free, you'll thank yourself for it later on.  Make sure your harness fits properly.  Those tanks are pretty heavy and will flop around and make things no fun.  Take it slow, have fun, and don't get hurt.