WARNING: Do not trust that eBay "kaya" board to be real kaya. A genuine kaya board of any serious quality is, and has to be, quite expensive.
I completely agree here. That board you posted from Ebay looks dubious at best, though that could just be because it's old (Kaya darkens with age). I don't think it's Shin-Kaya (the lines aren't well pronounced) but I'd avoid it nonetheless. I see sellers on Ebay all the time saying they're bowls are "Mulberry" when they're just Chestnut; or trying to pass Katsura or even worse Shin-Kaya as the real Kaya.
A couple of points to watch out for (I know I'm going off on a tangent but bare with me). Going off of pictures alone, Shin-Kaya usually has a VERY pronounced and dark grain whereas Kaya is generally subtle and and light. Kaya usually has a much closer grain than it's imitators due to long years of growth.
Based on my observations, Mulberry bowls will almost never have an Itame cut. The wood is just too expensive to waste and it's quality demands masame.
In my opinion the quality of wood for Go Boards is as follows...
1. Japanese Kaya (Especially Kaya from Miyazaki-ken)
2. Chinese Kaya
3. Katsura (because of the size of the trees the cuts for Katsura are always Itame)
4. Agathis
5. Most everything else
6. Shin-Kaya (Alaskan Spruce) (I have no love for "Shin" Kaya!

)
If your willing to wait a few months and don't mind dealing with a third party I recommend ordering a board through Yahoo Auctions Japan. You'll need to go through a third party site if you're not actually in Japan. There's a few services out there and I recommend shopping around.
Check out this seller. He makes boards from Chinese Kaya and sells them on Yahoo Japan for a very decent price. With surface shipping it'll be about the same price as some of the boards you're considering but at a much higher quality. Make sure your buying a Go and not Shogi board since he sells both

. I have a friend in Japan that bought one of his boards and it's rather nice, not the same quality as Mr. Kuroki's but a good substitute.
http://openuser.auctions.yahoo.co.jp/jp ... kayakoubouIf I had to choose one of the boards you listed, I'd pick the Agathis board from Yutopian. It seems the best cost for what you get and looks rather nice.
Anyway, I hope this helps!