About the smallest and certainly the cheapest (price wise) Kayak I regularly use in the ocean is a Malibu Mini-x.
It's small size 9'3" and light weight make it great for surf launching in hard to get spots where you have to walk in, and it handles great in the surf.
I probably fish my Mini-x as much as any of the yaks I own. Just because it can launch almost anywhere through anything and because I can leave it in the truck. I like to take it with me when I go on trips out of town for work, and fish it a lot in lakes. Also great for river fishing. Basically just a great little kayak for the money.
They are not fast but they are very stable and seaworthy. I'm 6'1" and 185 pounds and it's more then enough kayak to float me and my gear. Probably cheaper to ship down Ecuador then a big kayak.
Though I've fished mine at La Jolla I would recommend them for fishing there or anywhere you have to paddle a long ways, but if your not going far and want something that's cheap and easy to fish from I'd recommend one.