When i was still learning there was the opportunity to get a good discount(as long as you currently go to a university or do an apprenticeship(germany) ) on laptops. I bought a powerful portable think pad that has served me well so far, and i paid 750 euro for a top spec model i7 16 gb ram 256 gb ssd. When i now think back i could have gone even cheaper i5 8 gb 256 GB ssd would have also been enough. When your just starting and don´t know which direction it will go maybe don´t look at the expensive very shiny nice ones. If you get for example a contract with some business it could be that they will offer you a laptop for work and your new shiny mac book air might stay at home as long as you work there because they don`t allow you to bring your own device into their network. I would suggest you to go with something simple which will for the time and then see how it develops and what you specialize in.
Maybe reconsider those 2, and look for something else, i don`t know if there are any good discounts for students in the UK.