A kayak for larger people or for longer trips is the Great Auk. 17' long and 24" wide, but surprisingly fast due to an almost plumb bow and stern.
Her little sister is also worth considering if you need a very short, light boat that you can throw on the roofrack with one hand and poke into the tiniest channels with, although amazingly short at just 10', she is nimbler than you would expect.
For someone who prefers something longer and narrower, although still capable of carrying a full load of gear I recommend the Expedition Single. 19' long and 21" wide, yet maneouverable and nimble