A very quick Amazon.com and eBay search showed several cai dao knives being sold under the Penguin name on each site. The cheapest price was Amazon, where the price was $11.50 and included free shipping (probably only if you were buying more than $35 in the same order, if I recall Amazon's shipping pricing). The eBay seller I saw was asking about $24 and was shipping directly from Thailand.
That being said, can't say I am all that familiar with Penguin knives. My only Kiwi knife (a nakiri) was nothing that I would want to keep, except as a reference. Really thin knife (somewhere about 0.05 inch blade thickness).
If I was looking for something that was quite a bit better steel and a comparable profile and thickness, I might consider a MAC Chef Series 8-1/2 inch HB-85 knife, which is 2.0 mm thick, and weighs 4.9 oz. It's not exactly a cai dao shape (it's really a gyuto), but at 2.0mm thicknessit's really thin and the street price through eBay sellers is just at the $70 mark. (Posted retail is $82.50).
Hope that helps