What CPU are you using ?? -- on most MOBOs if you are using a 150W or lower CPU you do not need all 8-pins of the 8-pin connector and can use the older 4-pin provided by older PSUs ! (just check your MOBO manual to see which 4 pins to use. The extra 4 pins just allow more wattage for those CPUs that need more power.
If you have to use all 8 then you'd want a 4 pin to 8-pin adapter (the 6 pin plugs and 6-pin to 8-pin adapters are for the PCI-e video cards not the CPU !)
No problem - Just looked at the MOBO pic on newegg and in the pic they even show the MOBO coming with 4 of the 8 pins blocked with a plastic piece so looks like you need to use the 4 pins toward the edge of the MOBO (NEar the SYSFAN1 plug) and leave the inner 4 empty ( See This PIC )