the items as listed are fine but the board is a
Asus P5AD2-E Premium
item 1 the spread the connecters and the PSU will balance the power.
item 2 there should be two sata connecters and possibly 6 Molex 4 pin supplied, the motherboard should have sata connecters also as well as IDE.
item 3 the PSU if bought in UK should have a socket and the fan controller at the back, if that is all it should be 240v.
item 4 Split the 20 and the extra 4 pin and isolate the extra plug the separate 4 pind P$ type plug must be plugged into the board at the top back.
item 5 do no try test or anything else a PSU is a dangerous tool and test like that sould cause injury or damage.
take it easy, read the manuals, take care and slowly, it will come together, go over each connection again before you finally try it.