A tripod will definitely give you the best stability. Get one with a leveller and with removable spreader if you are shooting in the wilderness etc. Spiked feet option is also a must. Carbon fiber is lighter and more rigid.
For days you don't need or can't use a tripod, a monopod is a good and light option. I use the Trektech mono/tripod walking stick. In tripod mode it's steadier than a monopod. It doubles as a walking stick as well.

Justin,
I suspect in post production you have used filter to get those beautiful images. Could you ask you what filter did you use?
Tahnks