You're suggesting sell the 1740, and get the 1022/70200 combo?
oops. sorry. i didn't realise you are asking for advise on lens purchase.
for your trip, it depends on where you are going, and what is your preference (are you a landscapist, a candid shot person, or animal person).
i would suggest UWA lens for landscape, although there is an alternative - do stitching to cover wide angle. this is labour intensive.