Hey Dman,
I am using a Zap Phase5 Wake Skim that is 54" x 20 1/2" and it is really the perfect size to use with a kite. Here is a link to there site:
http://www.phase5boards.com/productPropBoard.cfmI could see going a bit smaller, maybe 48" or 50", but 43" seems too small. Especially @ 190 lbs. I weigh 160, and I can start having fun in 10mph with my 12 CB3. Although, I would say that the skimmer you are looking at is relatively wide for its length, and that can make a big difference as well. Does it have some volume throughout the length? How thick is it?
What wind conditions are you mainly riding in, and what is the type of kite you want to use with it? Most of the traditional skims are too small or narrow to ride with a kite in lighter winds. One thing I have to say though, is at $79 it is hard to go wrong.
Did you check out the skim video on the site? In that video I am riding the Zap in anywhere from 12 - 22 mph and I am using a 9! I prefer to use a slightly bigger board, with a smaller kite. I find it is more enjoyable, but that is just my taste. Let me know and I can give you more feedback.