If you want to take a look at a good selection of headsets, why not plan a x-country flight, eventually, to a field that has a decent pilot shop? I'm not based in the UK so I wouldn't be able to suggest one but there has to be a few good pilots shops at airfields within a reasonable distance. If it's far away, try to hook up with a fellow student who trains with the same instructor. You fly one leg, he flies the return leg.