I cant find heston blumenthal's recipe online but this one looks very similar: It's half way down the page
http://www.dadsdinners.co.uk/
Heston's difference was that he used italian "00" flour, live yeast, buffalo mozzarella and made his own passata (by pressure cooking large cherry tomato flesh for 5 hours with oregano, bay and tyme)
To get your oven hotter than the dial allows put the grill on full after the oven's reached max. Use an upturned cast iron frying pan that's been on full heat for 20 mins to put the pizza on. Place it high in the oven so the pizza's near the grill. Should take a couple of mins to cook but i havent tried it myself yet!