It won't really sound the same for a couple of reasons.
1. I don't know if it was ever verified that the ES10 and the AD2000X use the same driver (I'll have to check with Shigzeo) because Audio Technica repeatedly states that the AD2000X uses a permendur magnet (like the W5000 and other high end AT cans) and does not list the same information for the ES10. It seems more likely the AD1000X and ES10 have a similar driver.
2. On the AD900X the driver itself is angled, whereas on the AD2000X the driver is flat and the baffle is angled. That means the distance of the driver from the ear will be different in both headphones, which usually makes a pretty big difference due to the change in air damping.
3. The AD1000X and AD2000X use a different diffuser pattern in the earcups with curved fins. While I can't say how much of a difference this makes, it is responsible for some of the difference between the sound of the AD900X and AD1000X.
You could probably do a better job by buying the AD1000X and implanting the AD2000X drivers in it. Order the AD2000X drivers as replacement parts. That said there is not a great deal of information suggesting that the AD1000X and AD2000X sound all that different. It would be a terrible thing to sacrifice a perfectly nice ES10 for a project like this...