SP FFMs tend to be a bit disappointing, I think I've only ever had one good one in almost a decade of punting.
Best FFMs I've experienced have been with a civvie + submissive SP, with the civvie armed with a handycam and directing the action.
The civvie herself was unfortunately mad as a box of frogs, so the relationship itself didn't last - but the handful of videos she took I will rewatch again on my deathbed, no doubt !
One trick I've found, with both SPs and civvies, to see if they'd be interested in more than 2 bedroom participants, is to put on some porn, and see if they keep checking it out during your session. More likely with Thai and English SPs, never had any luck with Roms or Chinese.