That monitor looks decent for the Price.
Mouse and keyboard can be a good investment if you buy right the first time and you take care of what you buy. Some mouses and keyboards are known for ware and tear though due to being used so much.
I would recommend a g5 or the Mx series as they are sturdy and mine has served me a good year so far with hardly any diffrence.
As for a keyboard.. Well you really can't go wrong...just buy the one you like, I only wanted my g11 for the glowing back lights
I would get a g15 though, because at the time my g11 was really cheap, but now they are close to the same price.