The skin looks best when your imvu client is in accelerated graphics mode.
The tail is found under Male Accessories.
I don't own Okami, Clover Studio does.

Paws and ears are not included.
Ears: http://www.imvu.com/shop/product.php?products_id=40280
Paws: http://www.imvu.com/shop/product.php?products_id=121672