Hi Jo and welcome to the forum. If you go into the search feature near the top of the page and type in both names you will find several informative dialogs on the two. They'll give you a pretty good list of pros and cons of each.
They're both constrained as to how much gear you can pack, but with its longer range, larger carrying capacity and foredeck the Oasis sounds like a good choice for your needs.
Stringy has done some over night excursions with his Oasis -- be sure and check out his excellent posts. Here's a good start:
http://www.hobiecat.com/community/viewt ... oasis+trip
