xerox 560 vs konica minolta c6000 or some other brand machines equal to this category

Hi all,

I m new to this forum. i have a printshop in chennai, india. Now im using Konica Minolta C224E. It is good to its cost but in some of the areas like gradient effect, grey mixture not good at all. It has very bad printing in these areas. And im not blame this one because i know it is 600 dpi print resolution.

Now i want to upgrade to one of these machines like xerox 560 or KM c6000 or some other brand like canon or ricoh also ok if fine means.

My monthly 12 X 18 size print quantity is around 2000 copies and 1000 copies of A4 size. i dont want speed & excellent quality but good quality prints.

and i also want low per click charge.

machine preference is both used & new machines.

do anyone of them know about these machines?
any suggestions or help or opinions would be appreciated.