Get the G65. That will be a dream board imo. It's only a bit more than the g45 too. Get the 7850 and save a ton of money, then wait until October when AMD launches their 9000 series gpus, then buy something from that line.
The Z87-GD65 is £154, the Z87 G45 is £120. For £10 less than the XFX psu I could get a 600w psu, and for an extra £10 I could get a 750w psu, is the XFX really better? Also I could get a used 7850 for £135 or a new 7870 for £163, which one?