One of them is 22", while the other is 24". I'm planning to use it mainly for gaming, mainly FPS, and I sit about 3 feet away from the monitor (in case that's important in any way).
The 24" screen is 21£ more than its 22" counterpart, and apart from the size it only wins in response time, having 5ms (2ms GTG) while the other has 16ms (4ms GTG). The 22", however, has a 5000:1 contrast (20m:1 dynamic), while the 24" has only 1000:1 (12m:1 dynamic).
So, bottom line, how important is response time? And how important is contrast? And do 2" make much of a difference?
Neither of them are great, but of the two, I'd definitely go with the 24" one.
The smaller one has a response time of 16ms - which is absolutely awful. The 24" one has a response of 5ms.
As a rule of thumb, for gaming, the response time should be as low as possible, and should be (at absolute maximum) no more than 10ms. Therefore, the smaller one, with a response of 16ms, is completely out of the question.
Contrast ratio is important, but not as important as reponse time, so even though the smaller screen has a much better contrast ratio, the extremely slow response is more than enough reason to avoid it.
OP, do you like in UK or USA?
I noticed you put 125£, which lead me to think you live in the UK, but you put "£" at the end, which is unusual. Maybe you meant 125$? In which case, I'm afraid you can't buy from ebuyer, because you live in USA. Those screens are out of your budget when converted to $ as well.