Headphones or earphones?
Headphones there are 3 main choices in the market
Seinheisser PXC550
Sony WX1000M3
Bose QC 35
Which one is better if up to you they are all excellent, go to a store and try all of them yourself. I’m not sure on the UK price, if I do a simple currency conversion from over here then all three of these headphones would be between 200 and 300 pounds
There are other brands now entering the market from what I’ve seen but the above 3 still remain the go to recommendation
For 100 pounds that could be tricky, as above that akg ones fit the bill but they looks cheap, aren’t over ear and may not be noice cancelling (if noise cancelling is important). But more models will keep entering the market as jackless phones continue to become mainstream.
The main problem is using headphones in a office, if there are many others doing he same you can get interference