I'm in the research process right now. Here are some helpful reviews put together by coffee pros for the NY Times and Wire Cutter.
The grinder is so important that you are better off having your coffee supplier grind them for you in their professional machine if you can't afford or don't want to pay for a high quality burr grinder. They say even though you lose some freshness with preground beans, the result of just having them grind for you and losing some freshness is still light years better than the garbage you will get from using the freshest beans in a bad grinder if you can't budget for a decent one.
https://www.nytimes.com/wirecutter/r...r-for-espresso
https://www.nytimes.com/wirecutter/r...offee-grinder/
Also check out James Hoffman on YouTube. Lifelong coffee industry pro and World Barista Championship winner in 2007. He does a ton of reviews of machines for all budgets, grinders, accessories, you name it. Great channel.
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