Thanks for the comments so far. I think the Dura Ace C24 will be outside the budget.
My thoughts are with the Mavic Ksyrium Elite option or Fulcrum Racing 3.
I have a concern about making the jump to tubeless, and the Fulcrum option has a 2-way fit option to consider. Any thoughts between the two?
Cero AR30 from cycledivision are hard to beat for £300, I use them for training wheels on my race bike and it’s hardly worth switching to my tubs for racing! And although I haven’t used them the AR24 for £190 is probably an even better deal given the money you’d have left over!