Yeah I noticed that too, on further looking. It appears that the way Euro Car Parts checks fitment for various cars, is wrong (its been wrong on many other occasions for other parts I've tried to get from them, and eventually gave up in favour of GSF who are slightly better). So they're a bit naughty to list that headline price but offer only 540cca, instead of 570 or 600.
Alpha batteries are really good, I've used them before and nobody could match their price once specification is like-for-like. I emailed them and they've confirmed that a 334/250 upgrade should fit after checking:
072/089
£64.99
72AH, 600CCA
255L x 173W x 182H
334/250
£74.99
90AH, 800CCA
306L x 175W x 225H
A quick check under the bonnet suggests it would fit, but I'd need to adapt/replace the battery clamp so it reaches over the taller battery (the bonnet clearance should be okay though).
Anyone fitted this or another higher capacity, and if so, what type?