Just a word of warning: it's in 2 parts, with no chance to heal up in-between, and they're both long.
My advice would be to take lots of high value healing items. I ended up using several nectars, not only because they healed all HP/MP, but they cured status ailments at the same time. I was playing in 'normal' mode, with everyone level 29, which maybe was a bit low. I used Bel, equipped with the Boss Goggles so that she had high enough speed to get in first and heal up anyone or cast status boosting spells before anyone else did anything.