Mixing 23.98 and 29.97 footage in FCP6

Hi,
I'm hoping to start a new project off on the right foot - here's what happened last time:

I just finished a documentary shot at 23.98, sequence/compressor preset of HDV 720p24 (in FCP 6).

After mastering I was told that not only is HDV out-of-date, but that all of our future broadcast docs will have to be converted to 29.97 anyway - so it's best just to shoot and edit them as such, in a more common format (ex. DVCPRO HD).

I want to make the next project easier and follow this advice, but am already finding myself confused.

The next project has been through many rounds of filming already.
The older footage is all compressor setting: HDV 720p24 - 23.98 (1280x720)

Other, more recent, footage includes:
compressor setting: XDCAM EX 1080p24, 23.98 (1920x1080)
compressor setting: H.264, 23.98 (1920x1080)
compressor setting: H.264, 29.97 (1920x1080)


Moving forward, we want to shoot all Doc related footage in 29.97 - but until then, how do I proceed with what I have?
I can't seem to get the right sequence settings for my 29.97 footage without having problems.
And I know that it will be best to convert my 24 footage to match my 30 footage in compressor, but am unclear which settings to use there as well.


Please let me know if I can offer any more explanation.

Thanks in advance