Replacement for HP Colour LJ 4600?

[sidewinder]

We have a Colour Laserjet 4600 as the main (pretty much only) colour printer in our school. It's 9 years old and has been having major problems with the paper trays. Considering the cost of repair and the age, I was considering buying a new one.

 

I was thinking either the CP3525n or the CP4025n which may be more suitable as it is faster, higher resolution and has more memory.

 

We also have a few Canon i-Sensys LBP7750 around the site which I like, but not sure if they are up to the job as a fast reliable printer..

 

Only need A4, A3 would be nice but a decent one is probably outside of our price range