I tried running SPC but it looks like the Acquisition board I have purchased is faulty. SPC fails and channels 3 and 4 are unstable beyond 2.5GS/s.
I might re-visit the original Acq. board - it has one faulty trigger chip which only affects channels 3 and 4.
Apparently the Tek # 156-8278-00 chips are unobtainium.