GBr LED backlight is very tricky, it needs very good colorimeter - I highly recommend NEC SpectraSensor Pro, which is the best choice especially for PA242W display, so go for it!
The 10nm resolution of X-Rite i1Pro spectrophotometer is not sufficient for GBr LED backlit display IMO, and 5nm spectroradiometer like Photo Research PR655/670 costs a small fortune (13-20k$ plus 5nm option fee).