The Kinvara is a performance trainer, so most performance trainers from other brands would be similar.
Example:
New balance: Zante and the Vazee Pace
Brooks: Pure Flow ( but their latest model is terrible, and they have gotten away from what made the shoe so great)
Nike: Zoom Elite 9, Lunar Tempo 2, and the Flyknit Lunar
Adidas: Adios Boost....The Takumi Sen is adidas' true true racing flat. The boost can be used as a flat or a performance trainer. The Adios is more of a hybrid.
Asics: Hyperspeed...It's listed as a flat, but I don't see it as pure racing flat, because a lot of people use it as a performance trainer. It is comfortable, and carries a sufficient amount of cushioning for long runs. You could throw the Fuzex lyte and Fuzex in there as well, but those shoes are about 1 ounce heavier than the Kinvara.
Mizuno: The Hitogami is definitely similar to the Kinvara, and can be used as a flat or performance trainer.