I'm no naval designer or architect but Bob Perry is and he is a member of Sailnut who checks in from time to time. He might be able to give you insights that I certainly cannot. If you get your post count over 10+ you could send him a private message (PM) and ask him directly about your dilemma.
If you look at the world wide distribution of Morgan sailboats: Boat Database Statistics
you will see that while many of them are in the US there are quite a few in the Mediterranean and elsewhere - so they DO cross oceans in them. That distribution represents ALL models of Morgan sailboats though and not just the M33.
I think that a lot depends on how you want to use your boat and where you want to be able to sail to. If you want a bullet proof boat for doing a circumnav than I'd follow in Donna's steps and refit the SC double ender but for less adventurous pursuits it may not matter so much and the Morgan 33 might be just fine.
I'll send Bob Perry a PM and ask him to look at this thread for you.