Need replacement for kholer Serif toilette

[Kitui]

Finally the Kholer Serif toilette gave up. It was easy to cloth and not water efficient. We need to replace it and I have not worked on toilette replacement for a while. What do I need to consider to have the right fit? What is the best toilette (teenager proof) I can replace it with? I have a Toto with tornado flash and love it but I would love to have a bidet fixture too included in the replacement. Thanks
Need: confort height