Fantastic studio, absolutely incredible!
I think you could need:
a good drumset (Ludwig)
some nice guitar and bass amps
Roland space echo / Binson echo
Then it´s an excellent idea to have a 60ies looking furniture (should be called Giftschrank (poison locker)) for ProTools, I would add one stereo parametric EQ and one digital reverb.
I have two WSW transformer looking exactly like the one´s in the directout mod picture, pm me, if you need it.
All the best with the studio!