Tonearm for Technics SP-15

I have a Technics SP-15 turntable with a Grace 707 arm and a Grace F9E cartridge with a Soundsmith new stylus.  This combination sounds great but is limiting.  The 707  tonearm has a fixed headshell and it does not allow me to easily swap other MM  high compliance catridges or match compliance requirments MC cartridges.  Suggestions welcome from those more expert than I.  


Acos Lustre GST-1 appears to have an early version of their VTA on the Fly.

Would GST-1 fit on a Technics SP15?

do we like this arm? concerns?

Does anyone know if the gst-1 will fit on the SP15?

spindle to pivot ____mm ?

pivot to back of counterweight?

height of gimbal from top of arm wand?

height: to get ’up’ high enough for the SP15 platter height, is a spacer below the arm needed, or the arm post long enough?