here is the spec sheet for this toilet. They do not provide that dimension, however the main dimension you need to make sure it will fit is the Rough-In. The Rough-In for this toilet is 12".
A washlet is a bidet seat. A bolt down lid is more for commercial applications and prevents people from taking the lid off the tank.
CST743E#01 does this product has a g-max flushing system?
This model has the E-max flushing. If you want the G-max you would need the CST743S#01 Follow the link below.