What laptop to buy

zebrastacker2004​  In terms of performance, the graphics chips are about the same, with each one winning on some benchmarks.  The variance seems to be less than 10% in either direction, so it's close.  I can't tell you which one runs Sims 4 better because I don't have hard data on that, but you should be okay either way.  So you can choose based on whatever matters to you.

If you don't want to spend the extra money, then don't.  If you want or need extra storage, the £300 option is clearly the best.