[Perfectlap]

I would recommend the Griot's Garage clay bar simply because that's all they sell you, the clay. And they give you a good amount in a plastic jar that keeps it from drying out. Almost every other brand add a quick detail spray to jack up the price. Which is silly because all you don't need QD spray, any basic car wash soap diluted in water will work. Or you can simply clay while you're washing the car. By the way, It's actually not clay but play-dough type plastic.

I would caution you on using microfiber repeatedly on the paint. Those towels are really overkill for a well-maintained paint surface. You can easily do more harm than good. In many cases microfiber towels just re-branded janitorial towels used to clean linoleum floors. The big problem with standard auto store microfiber towels is that after the first use they are a real PITA to get back to 100% clean. I've run them in the washer 3 times and those hooks on the prickly side of the towel still had little bits. Get a few buffing towels for those final passes and for using sprays I would recommend long nap towels (no prickly side) like the Griot's Garage green and blue towels. Chemical Guys and Poorboys World sell these towels as well. They're not cheap, usually at least $3 per towel but they'll save you the expense of a buying an orbital polisher to get out all those swirls.