I want to be able to deposit money and act fast, not wait 3 days.
Maybe in this case buying with credit card would be the choice for you. But beware, it's usually more expensive than bank transfer.
I don't know and I would not expect to see Binance has better banking support than Kraken. So I'd simply pick something that uses the services of an UK bank (but unfortunately I don't have a good example or recommendation for you)