few questions first!
are you planning on getting a dual element colo stone? if not the only real elements you can be is water/earth (with earth being the "main" element)
i know the advantage of dual element is multiple 5th tiers but shall ask anyways. are you planning on getting two 5th tiers?
would you prefer more higher level attack skill, higher level misc skills, or some kind of balance between the two?
also in the event you get bored of waiting, dont like my advice, or just want to experiment on your own you can use this for help
unless you can read japanese you can match up the icons and use this for the skill translations
Elemental Master Skills - ggFTW La Tale Wiki