Ivan was a marathon paddler, not sprint. He is a big, powerful guy, famous for having a very strong fast finish in races.
You can't compare sizes directly from one paddle model to another. The shape can have a huge effect on the 'grip' on the water.
I use a Jantext Gamma Rio medium minus, which has an area of 740cm2 (bought from Ivan, incidently). That paddle has incredible grip and feels like it is planted in concrete. Before purchasing the Jantex, I tried about 6 paddles. Some, with bigger surface area, were 'sloppy' in the water (I think because of twist in the blade). Twist, to some extent, depowers a blade (but makes it easier to get a smooth, non-plopping catch).
If you can, (beg, hire) try multiple paddles. What is perfect for one person might feel terrible for you. Don't rush into buying a paddle.
I paddle a variety of club boats (K1) and find it much, much easier to adapt to a different boat than a different paddle.