Hi thanks for the replies man, sorry I haven't been at home for the last day.
In the end with the help of some friends I managed to fit in in, I worked out in the end I had to remove the black thing but then the problem were those SATA cables you mentioned (they plug into those orange thingies). In the end I unslotted both and moved them to the slot below but then my PC wouldn't start up, moved them back up and the card wouldn't fit but the PC started. Thought it may be my PSU but I swapped them around (left to right, right to left) and moved them down so the card fitted and it worked. I just get another weird startup screen tho, dunno if that really matters.
Funny thing is I don't have the new PSU yet but the card has been detected and installed fine. Haven't had much time to test but was running around Oblivion with everything maxed without my PC shutting down. Could be that this PSU is actually a pretty good one or something. The fit of the card in the case is VERY tight tho. Takes a good 20 minutes to put it in. It is also skew and resting on the top of the HDD. Hope this won't cause problems. Will post a pic of it soon.
One last thing is that I don't know how to disable the integrated card. Is there such a way?