Too much to put into one reply. Use the 'Search' function and search for 'Oregon 511a', or 'Oregon grinder' and you will get back pages of stuff.
My opinions:
- The Oregon, or similar Jolly Star, Speed Sharp, etc. grinders in the $300 - $400 are worth it. They are not perfect, but better quality than the $100 'look-alike' grinders. Less fussing to get them to work right, parts available, hold their value if you want to re-sell, etc.
- The Oregon and Molemab wheels (sold by Bailey's) are good quality, conventional abrasive wheels. The ABN or CBN wheels like the Dynasaw ones get good reviews here on A.S., but they are expensive. You need a couple of sizes to cover most chains. If you can afford or justify them - great. But maybe start out with the ones that come with the grinder and decide to upgrade or not later.
Grinders take a little skill to master. Use light 'taps' to avoid burning cutters. Dress the cutters frequently to expose fresh abrasive. Again, lot of good info in the threads above, on mounting, use, technique, etc., if you do the search thing.
Philbert