Most of the regulars on this forum prefer the Toto line of toilets. They can be reviewed elsewhere on this forum. One piece have their advantages. Most models are easily installed DIY. Since you purchased your AS, times have changed. The famous name manufactures have sold out and do not have the high quality their name was build on. Toto is the largest manufacturer of toilets in the world with many models to chose from. You might be well advised to peruse the threads on this section of the forum and get some ideas.