Try to get a system with a way to reset the ink chips (makes you reset or replace the printer cartridges). The ones that say they have auto reset have never worked for me.
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xcontinuous+inking+system.TRS0&_nkw=continuous+inking+system&_sacat=0