I also use the Mequiar's tire gel.  Been happy with both products.

I quit using the Meguiar's gel and went to 303 Protectant.  Way less messy, easier to apply, and leaves a nice satin finish.  I don't like super shiney tires.

I also use scrub brush and some ajax powder. Works fine.

For long time now I have used Meguires "Endurance" - just a little, applied with a clean cloth  It gives a little shine, but not too much.

To keep the white letters clean I use White Spirit, which you guys in the US call "mineral spirits" I think.   I go over each letter individually, using a clean section of cloth each time.    It's non abrasive and non corrosive, keeps them really white and I find I only need to do them perhaps a couple of times a year.   Between that I just wipe the tyres down after each run out.