These are exactly the types I meant (finger problems made me type "power" instead of "powder coated" in the post above).
They really are no maintenance, and can be left out all year without covering. My own preference would be to use iron/steel rather than aluminium (which because it's so light can feel flimsy). After that, it's just a matter of finding a style (and price!) you like.
BTW: I saw some in M&S the other day, to add to the list.
Got the Torino set from homebase, sturdy but not so heavy that you would never move it again. easy to put together too. very happy with it, cushions are included in the priced and are attached with strong velcro tabs.