We might be talking over a meter and a third tall when finished.
I've already played around with the greaves quite a bit combining the best features and adding modifications I deemed necessary (But nothing is etched in stone I hasten to add.)
First I do not hold with the Space Marines rattling around in the greaves trying to stand on a shifting floor with every step the Titan takes plus when the model is static say on a shelf I plan to display him in the classic Emperor pose with legs slightly spread, greaves at an angle to the ground/shelf for maximum stability.
A pose I'm sure a working Emperor would take when firing at an enemy. When you speak of Infantry I presume you mean Space Marines.... I'm not up on Titan lore but I was under the impression that they transported armoured combatants (?)
I plan to have my Marines held in place with harnesses as in the 'Drop Pod' model which would be the only way they could survive the walking jostling.
Once the Marines prepare to disembark the Titan can assume a stance that is more conducive to discharging the personnel.
I've always felt the main body of the Emperor titan held all the business end of the of the vehicle; Command deck, Engineering, Reactors, Machinery.
The top hamper being reserved the worship of the Machine God Omnissiah or Deus Mechanicus the supernatural entity worshipped by the Tech-priests and other servants of the Adeptus Mechanicus as the embodiment and bestower of all knowledge and technology in the universe.
Other than the manufacture of the deck I've done little in planning the superstructure which will be a project almost as big as what has already been done. I do have a Skitarii crew and tech priests and Belisarius Cawl to inhabit the deck once completed but all that is far off even in the planning stage. :D
Right now I have the model sitting on the floor of my den. Even without legs it's two feet tall and I'm wondering what to do with it when it's done. We might be talking over a meter and a third tall when finished.