if I was buying off the interwebs and was just suggesting a wash, clay and polish kit with a wax I would suggest the following
wash - bilt hamber autowash
clay - valet pro poly clay bar 100g (enough for 4 cars)
clay lube - dodo born slippy refill - make a solution up in a spray bottle as the dodo ones are crap
polish - dodo lime prime
wax - collinite 915 - has a good quality finish and is very protective
I haven't priced that lot up but you should be able to get it all, plus all the microfibres and applicators that you need and a drying towel £50/£60