I bought a 2-sided 400/1000 diamond stone on sale a few years ago; the kind with the plastic substrate. The diamond surface substrate has delaminated and its time to upgrade. I intend to sharpen chisels and plane irons and would be looking for 3X8 or larger surface. Any thought on the 'best' combination of grits, either on a single substrate or multiple stones, and specific models or brands would be greatly appreciated. Price is not an obstacle but I'm always interested in a good buy as long as the quality is there. Thanx in advance.