Kohler makes a good tub. But, have in mind than an ofuro in Japan is not use for washing. It is used for soaking. The Japanese shower to get completely clean before entering the tub to soak and relax.

I lived in a Japanese house in the 1950s, and it was an experience. Just imagine a Japanese winter in a house with paper walls and no central heat, just charcoal-fueled hibachis.. It redefines your understanding of cold. So a heated soak in an ofuro was prized since it allowed you to get warm. Getting out was a bear, though.

Since you don't mention the dimensions of the space you have available, I cannot suggest and alternative, but there are short tubs available that are designed for washing, not soaking that might be a better choice.