Just picked up a c100 the other day, it's a damn beautiful camera but the post workflow is giving me a headache.
With respect, this sounds to me like a problem you may be creating in your head. I can't think of any NLE that has issues ingesting AVCHD from a C100-generated wrapper.
Most "transactions" of file-based media - eg getting your AVCHD clips from point A to point B - involve some kind of wrapper or container, to hold the additional technical/descriptive metadata.
Avid, FCP, Lightworks and Premiere Pro all have super quick and easy ingest processes to bring the clips in properly. Premiere Pro and FCPX will also work natively with AVCHD, as Erik mentioned - although I personally prefer to work with a transcoded intra frame codec (eg ProRes 422.)
I've gone down the Ninja Blade/ProRes route, as it offers such a fab monitor solution, but I actually miss the beautifully compact file sizes of AVCHD and the ease with which rushes can be archived and retrieved at a later date.
To answer the original question, I suggest:
- Shoot parallel onto Dual Cards - one for you to keep, the other to hand over to the client
- Find your sweetspot card size for client cards. It's a tradeoff between media cost and redundancy. For most shoots, I suggest 16GB cards are about right. Cheap to buy, not so small that you're handing over a box full of cards (extra ingest time) or too big, that you're risking putting all of your eggs in one basket.
- For the card you keep, you could run a larger 64GB card that just sits there, growing in size across different shoots. Or you could be super safe and run a brand new card for each shoot and archive that as a backup for your client.
Cheers,
Ben.