Vertex animations through code is also abit easier as handling bone animations through code. So logic, the blending part would be more complex when using bones But whereas the animations itself can be created more smoothly via bones than doing it the vertex way. Thus the more complex animations are handled via bones. I hope you find your model, turbo squid has got some fine models which are available for free

http://www.turbosquid.com/

Cheers

Frazzle