Ok, so pretty much I have these options to increase the power of my Mac:
1)
Radeon HD 5770 1GB (270 pounds)
2)
Sapphire HD 7950 3GB (311 pounds)
Any other plug-and-play option that
dramatically increases the performance of my early-2008 Mac and that works both in Mac and Windows (Bootcamp)?
Regarding flashed PC cards, the guy you talked about ships stuff from the USA. Living in Europe, I really want to avoid shipping stuff from there because of crazy taxes.
I just want to keep everything simple. Order the graphics card from Amazon (UK) or something like that, receive it at home and plug-and-play. I don't really want to mess up my computer, since I'm no expert in this kind of stuff.
Gav Mack: that seems a bit complicated. I'm really afraid of screwing up.