Of those listed, Nautilus (no speed buff, but Hook can add mobility as well as good for chasing directly, can jungle, can support, has solid magic damage for the "tank" role) or Volibear (speed buff and slow great for chasing, can jungle, can top, is more bruiser and AD focused) feel like the most fit your criteria.
Cho isn't good for chasing, but does have good flexibility and functions well as an AP tank. Amumu is a little better at chasing than Cho by comparison, but doesn't have as much Flexibility. Sejuani is in a similar state to Amumu, though she's a bit better at chasing than him, but she also doesn't really function as an "AP Tank" rather than just pure tank.
Singed as already mentioned is a great choice if you don't already have him. Rammus, though slightly less AP focused and less flexible, but is a fantastic tank for chasing enemies, and is very capable of pushing if/when he's in a lane (both minions and towers).