Mark IV SDHC Card MAX SIZE - HELP

Hi & thanks in advance.

On my old Mark II, I shot with a SD card as back-up. I remember it had a max size limit, I think it was 2GB.

On my Mark IV, I cant find any info if it also has a max size. Currently I shoot with a 16GB CF card and I wanted to start using a back-up SD card again. Does anyone know if there is a size limit for the SD card?

I was considering a SanDisk Extreme Pro 32GB Secure Digital High-Capacity (SDHC) UHS-1 Card and also replacing my 16GB CF card with a 32GB Extreeme Pro.

I may drop the SD card down to 16GB, but still need to know if there is a limit on the size.

Also, does anyone know the size ratio between shooting full size raw on the CF card & full size j-pegs on the SDHC card? Can I get away with a 32GB CF & a 16GB SD?

Any info would be greatly appreciated.

Thank you.