FWIW, you can record in anamorphic-friendly modes on the fp, but you can't do it in raw (so you'll be limited to a mediocre h264). The trick is to use the director's viewfinder feature.
I ended up trading in my fp and fp-l because I realized I was never using them because they didn't actually do anything better than any of my other cameras - and when set up to record 12-bit raw, even with the darkpowerlabs rig, they became as big as my R5.
Thanks for the heads-up, though, on the KEH sale! I hadn't heard of it - my CN-E set (currently 14,24,50,85) just grew to include a 35. š