Generally they run negative camber from factory. When you lower it, it gets worst.
Those arms are for extreme adjustment if needed. You may find if you need upto .75 deg of camber adjustment, 1 set of offset bushes from whiteline will be enough. If you need more upto 1.5 deg you can use 2 sets of bushes. Check sydneykids prices, around $100 a set plus fitting, need to press the old ones out etc.
You can get rose jointed upper arms, cheap ebay ones for $100 or jap ones for upto $400 which give you plenty of adjustment as well. I know sydneykid does not like the rose jointed arms for street use.
Get your wheels fitted, get a wheel alignment and what it ends up at. Then decide if you need to adjust it.
Check the suspension theads for sydneykid's recommendations. Running anymore than -1.5 neg camber wears the rear tyres pretty quickly.