I like the 8mm Magnacores from Cottons - used them on everything so far with good results.
As for plugs I use the R42LTS AC plugs in my GTA but for my other cars with stock boost setting's I use the 43's,it's a little bit hotter plug which aids in startup and driveability,and as long as your not planning to run racegas and really turn up the boost they are great.
Steve