I have been using CG clay forever then the patent expired so It's whatever reputable brand is at a good price. I by CG when it's on sale. Optimum Poly clay is really good. It's cheap compared to other brands. I have also used Sonus which I liked a lot.
Clay Lube I use Garry Dean's IUDJ. I buy it for other uses: QD, spray wax, window cleaner, rinse less wash, pad primer and the list goes on. After it's diluted the concentrate size I buy makes 5.5 gallons at a cost of $6 a gallon. You can use UWW+ which is pretty much the samething and does the same stuff. I think UWW+ is a bit cheaper and just as good. I just like supporting the small business owner.