Which WotLK?

Hello,

I've reccently been playing MoP, however I've decided to download TBC and WotLK as well for when I get bored of MoP.

Can someone tell me what is the difference between the "Wrath of the Lich King" and "Wrath of the Lich King (old)" download links under the "download tab?"

Which download link shall I choose in order to play on Icecrown realm and what is the difference between the two download choices?

Thank you for your time!

Wotlk = Wotlk cleint with Legion models
Wotlk (old) = Wotlk normal

I recommend you "Wotlk (old)"

Can either Wotlk be used to play on Icecrown?

with Legion models? Can you elaborate on that a little bit? does it have Warlords of Draenor models as well?

Thank you!

Can someone please explain what it means when he says it has "Legion models" ? What does it have in game that is from Legion?

yes, it has WoD models.

You can play on Wotlk realms wiht Both client, it does not matter