well i have been sampling some game engines in the past few months, downloading any demo i can find looking for one i like.. but i dont believe you will find one that can import poser characters and bvh directly.. first of all game engines use low poly meshes.. even lower than the P2low models although they can work, but youre going to cut the frame rate way down. only some game engines use bones, the others use something like morph targets. youre not going to achive real time frame rates with poser models. thats why poser cant do it in real time either. depending on what you want to do with the game engine there are several good ones out there... so far i like conitec's 3D game studio. has lots of good features, looks nice and simple to use. lots of free resources out there for it also.