Well I'm off to bed now (which actually means crashing out on the sofa and being attacked by five cats, taking it in turn to keep me awake) but, if you'll settle for a slightly lower ABV (of around 5%), but still with loads of flavour, you might like to look out for Shepherd Neame's porter, which Sainsbury's sell as their own-brand 'London Porter' and Asda sell as their own-brand 'Whitechapel Porter'. It's superb. (I had a bottle just before drinking this Belgian beer. They were the only two bottles of beer I'd got in the house).
Similarly, if you get into a Wetherspoon's house in the near future you might come across an American (I joketh not!) porter on draught, brewed in this country by Adnams. There are two versions, 'Importer' (4.2% ABV - excellent!) and 'Exporter' (6.2% ABV - untried by me but others say that it's great).
Another strong-flavoured beer I've recommended on AB recently (and which seems to have got Tonyav addicted to it!) is Marston's Oyster Stout, which you can find in Tesco. (4.5% ABV).
Good night!