Overclockers.co.uk actually ends up being cheaper than Dabs in almost every case, although sometimes not by that much depending on the product. The selection with OcUK is quite a bit better though.
With OcUK right now, Gigabyte board is now £93.99 inc. VAT, and the exact same Corsair can be had for £93.99 inc. VAT too, saving you just over £14.
However, the E6300 Retail is £135.11 with OcUK and OEM without heatsink is £126.89, so the one you selected at Dabs is highly likely not to include a heatsink at that price. Dabs' site does not state whether or not it comes with a stock heatsink (at the price, I suspect not), so a direct price comparison is not possible here.
As for the recommendations for the PSU/Graphics:
£88.11 inc. VAT - BFG 3DFuzion GeForce 7600 GT 256MB GDDR3 TV-Out/DVI (PCI-Express) - Retail (GX-025-BG)
£64.61 inc. VAT - OCZ ModStream 520w ATX2.2 Power Supply (CA-017-OC)
Source = Overclockers.co.uk