i thought of that twoo. today... =)
i would suggest a very big tube, like 500meters (/) (diameter)
no sucking at all, just put that in the water, on a floating plattform, nearly to the bottom of the seafloor. you even do not have to fix it on the floor, because, as we all can see in the feeds, the plume flows straight up. a 500 diameter tube wich is hovering the last 50 meter over the water, like a big silo or tank, where the oil is collected and shsips can suck it off and bring it away.

you could build the tube from segments with big cranes or robot-arms, wich are on the floating plattform. the segments come with ships. you put one segment on tob of the other, so that the tube would "grow" in the deepth.

with such a diameter there would be no need to suck, and no risk of methane hydrate. the oil simply floats to the top and finally swimms in a 500diameter tank on the water.