I would suggest North American on the west side.
In answer to your other question it depends on your interests. Just sightseeing and minor hiking probably 3-4 days. Otherwise more.
I am not a fan of the south section of Canyonlands unless your are hiking or 4wd stuff. Long way to drive. Stick with the north section just north of Moab - beautiful.
Not a real tough hike in Arches is up to Delicate Arch - go at daybreak if you can.
LOVE that area - have been there many times and spent lots of time there. Back again later this year.
For pix see www.LaurenBarbara.com and the Wanderings link on the left to pick the destination.
Enjoy.