Orange Box graphics card problem?

Ok, so I bought the Orange Box on my Steam account and I downloaded most of the games. The problem is that my graphics card isn’t enough to run it. It says I need a graphics card that has a minimum of a 1.1 shader or something.
Basically what I wanna know is where in the UK (London/Kent area)
I can buy a cheap graphics card with all the right specs to run all games from the Orange Box.
Preferably a big retail store like PC world, Game, Comet like average kinda London stores. Please don’t send me links to some online shops or some dodgy back street stores nobody’s ever heard of before.
So yea, if you know the specs for Orange box and know of a card a cheap card to get, lemme know the store or post the link to the product and specs.
Thanks in advance 😀 xxx
To AMD’s where can I buy that in the London/Kent ?