A decent signal gives you a decent spark as long as the plug is good. So in short all of the leads and points need to be clean/good connections to give that maximum signal strength.
As for spark plugs I went for the VAG ones from the dealer, you might as well do the leads as well if they are a bit tired, dizzy cap and rotor arm as well lol.
All in all I spent around £50 for the plugs from Seat dealer, leads from VW spares, rotor arm and dizzy cap from EuroCarParts.
All my parts were a bit tired after 60k miles (R Reg
ibiza gti) so I swapped them over and I swear the car idles better