yes, DMT extra fine is works for this (once you break it). I've been using this for the last 2 years. I recently got a naniwa superstone 1000 grit but often i still go to the dmt.

i believe there are otherdiamond hones, but i think sticking with dmt is best. these cannot be lapped, so it's important that they are flat to start with, and in my opinion it's not worth the risk going to unknown company just to save a little money.

as far as cost goes, i guess you can use a price comparison website.