I'm looking to set up Eyefinite but I've noticed that 23.6in monitors are ~$30 cheaper than comparable 24in monitors. If all 3 monitors are 1080p and 16x9 will I notice a difference in practical usage? Thanks in advance.
Your computer doesn't care what size your monitors are, just the resolution. The only differences are that it will be a little trickier to get set up just right and things moving between monitors might make a minor vertical jump.
Chances are your 24" monitor isn't exactly 24" anyway. Assuming there's about a quarter inch difference between the 23.6" and 24" screens, and you center the screens perfectly, there will be a 1/8" shift as objects move between the two screen sizes, at most.