Analogue-sequencer

You could try this:

Get midiox and midiyoke.

Use Midiox as your master time keeper, it has a cute little 'tape deck' 
controller box. Midiox can output both MTC and midiclock. Drive SX with 
the MTC from midiox via a virtual midi cable in midiyoke. Drive the P3 
from your ordinary midi output that midiox is set up to output to.

Yes, its a bit of a faff.

Alternatively, sell SX and buy Live. :-)

Mind you Live's not perfect either. PDC grumble, grumble...

Tony