so we got £240 for a monitor, keyboard and mouse. I can work very well with this. I will give you a few options. Going from low end of the budget to the higher end. You have all kinds of options.

But first! Peripherals are all very hard to suggest, if we don't have enough information. So I picked the ones that I find will work in most cases.
But there are a lot of things we need to know before we can suggest the right setup. But anyway, here is the list. No I won't explain to much why I picked them. I did went for these because I think they will work for "most" people. But if you got the time to answer the questions, I will have a better idea if my suggestion will work for you.

• Mouse: How do you grip the mouse? How many buttons do you want? I personally use 0 when I play any game.
  
• Keyboard: I recommend to go read about Mechanical Keyboards switch types first. Then after you know wich switch would be for you, you can give me that information. Then my other questions would be, do you want a TenKeyLess? Basicly numpadless keyboard. If you don't, do you want any "macro keys"? This can be helpful in some games, but in my personal experience I never used them when gaming. Only for some text macro's, push to talk, screenshot and other stuff. But not really to use while fighting a boss or anything.
  
  

  1:
  

  PCPartPicker part list / Price breakdown by merchant
  

  
  

  Type|Item|Price
  

  ----|:----|:----
  Monitor | Dell P2214H 60Hz 21.5" Monitor | £78.00 @ Amazon UK
  Other| SteelSeries QcK Mass Mousepad| £14.00
  Other| CoolerMaster Storm Devastor Gaming bundle (blue LEDs)| £30.00
  | | Total
  | Prices include shipping, taxes, and discounts when available | £122.00
  | Generated by PCPartPicker 2014-08-10 22:08 BST+0100 |
  
  #2:
  PCPartPicker part list / Price breakdown by merchant
  
  Type|Item|Price
  

  ----|:----|:----
  Monitor | Dell P2214H 60Hz 21.5" Monitor | £78.00 @ Amazon UK
  Keyboard | Cooler Master CM Storm Quick Fire TK Wired Gaming Keyboard | £69.99 @ Ebuyer
  Other| SteelSeries QcK Mass Mousepad| £14.00
  Other| Logitech G400s| £29.00
  | | Total
  | Prices include shipping, taxes, and discounts when available | £190.99
  | Generated by PCPartPicker 2014-08-10 22:10 BST+0100 |
  
  #3:
  PCPartPicker part list / Price breakdown by merchant
  
  Type|Item|Price
  

  ----|:----|:----
  Monitor | Dell U2414H 60Hz 23.8" Monitor | £167.94 @ Aria PC
  Keyboard | Cooler Master CM Storm Quick Fire TK Wired Gaming Keyboard | £69.99 @ Ebuyer
  Other| SteelSeries QcK Mass Mousepad| £14.00
  Other| Logitech G400s| £29.00
  | | Total
  | Prices include shipping, taxes, and discounts when available | £280.93
  | Generated by PCPartPicker 2014-08-10 22:14 BST+0100 |
  
  I just got negative feedback from other users for suggestion the Dell P2214H in a £1400 setup. But I highly doubt that ANY of those guys did any research about this monitor. I got the P2314H myself and it's an outstanding monitor. Here is a short review about the monitor and my god it's so awesome. The stand alone is such a winner for me.
  
  The 8ms response time is not noticeable at all when playing games, not even in shooters. No motion blur was seen on my side. Of course I sadly can not really say this about the P2214H, but it's the same series so I assume that they are pretty simulair.
  
  For the mouse/keyboard I would love to get the above questions answered before I tell you why I went with these products. I do know that in my keyboard part I only talk about mechanical. So if you think you don't like that, well then we have to go membrame. But do give me feedback about tenkeyless and macro keys. Thanks!