I've been using CaptainHook's LUTS as a starting point, They do work quite well, there are also some other LUTs I've been playing with. I'd like to try out Filmconvert but unfortunately I'm a bit low on funds for it, but I've heard great things about it!
Rec709 is quite ugly, I did a nighttime test on my BMPCC w/RAW (to see how far I could bring the image up in extreme underexposure. I prefer real-world testing over traditional camera tests
). The Rec709 version falls apart completely into nasty-bayer pattern like noise, where as any of the LUTs I've used have produced a slightly finer noise pattern that is completely passable after some Noise Reduction (using the demo for NeatVideo, full version NR would probably be better).
Regarding Exposure, I'd think that slightly higher exposure levels (ETTR as some call it) as it would apply to RAW. I would advise to test this - as this method may not achieve the desired result. I would also think it would be a good idea to test the images difference from the correct exposure vs. slight overexposure.
I'd say the best way to achieve the best exposure would be with a Light Meter for the most precision, although they tend to be a bit expensive. The reason I say this is that many monitors aren't fully calibrated to the image that the camera is producing, as well as potential flaws in the users view of the image (light reflections, smudges on the screen, dust, screen brightness, lower resolution viewing).
Captain Hook's LUTs:
http://forum.blackmagicdesign.com/viewtopic.php?f=2&t=19731&hilit=lutsFilm Print Emulation LUTs:
http://juanmelara.com.au/print-film-emulation-luts-for-download/FilmConvert:
http://www.filmconvert.com/purchase/default.aspxMy Nighttime Test (Be Gentle):
https://www.dropbox.com/sh/d9co6qsy23mf7x3/ghL0Jd4xjM