What I've seen/done orchestra-wise took place here at Capitol Paris or at Guillaume Tell and in both situations the SSL J series pres were generally used, then to Apogees running at 48kHz.
If doing a portable rig, I'd likely go with Millenia or GML mic pres for orchestra work with DPAs, Schoeps, etc. Some mics, like U67s and U47s, I like particularly when coupled with Neve 10xx pres.
As for converters, that's up to you (taste thing) and it also depends on clock source. Of the ones I've heard, I'd go Prisms or db tech, then Genexes or Apogees, then HD192s, then 888/24s, then HD96s, in about that order.
Capitol Studios - Paris, France