Cool Reader: I do not believe it has any ability to synchronize but might be worth checking out as there is a version with more control over refreshing pages made for the Nook. I have not tried it but it sounds like it does refresh as quickly as the built in reader. It also works with the Nook's buttons.
It looks like there are several options but no one program which does what I want If only Cool Reader would add synchronization or if Moon+ would develop a version optimized for the Nook.
Unfortunately I have not figured out synch yet, and the dev has talked about adding synch but I can't find any reference to progress.
How does Mantano do on refresh? Is it settable like CoolReader?