I can tell you this. It isn't overkill at all. I have a 30" and I think I can go a little bigger, then it would be overkill.
There is only one thing I would look out for, that is "color saturation" but not many manufacturers advertise this because they are mostly bad. Typical is 72%. I had an acer that only have 68% which is bad while I have a samsung which has 78% being really good. Or you can get a really really expensive monitor that has some ridiculous number over 100%
The other specs don't matter such as:
Contrast Ratio which is always 1000:1, but they would advertise a ridiculous number with dynamic contrast which doesn't really work.
Response time: You won't find a TN panel higher than 5ms
Viewing angle: Always bad, manufacturers exaggerate too much anyway
One more thing, What about brands? Obviuosly i wanna get the cheapest one i can and you can obviously get value brand monitors. Any brand I should steer clear of? or should I def stick with main brands? (i.e Sony,samsung,acer,etc)
BenQ makes good monitors. To be honest most products are quite similar if you are looking at average panels. The technology is so mature and hasn't changed for a few years now. You can't really go wrong.