The weight is between 51 and 55 tons. The power is 1200hp, and it's said there's a 1500hp engine. It's not amphibious.
For the 98 that is. Most estimates I have seen for the 99 is between 55 to 58 tons. The engine is now 1500hp.
It seems the estimate for the Type 96G (the Type 96 with the 99/Leo style turret and ERA) is around 48 tons now (dunno about the other Type 96 with the Merkava style turret). There should be a significant gap between the 96 and the 99 to justify the latter.