Have you looked at the Hannant's site H ?
But wherever you get them from, it'll cost a bit to get all sets, even though shipping won't be too much. I reckon the only reason reviewers suggest the vac-form canopies is because Hobbycraft canopies are not very clear, especially the 'angular' ones on types such as the Ju88 and Do17. They're not bad, but just not 'sharp'. But a good polish with 'T-Cut', then a dip in Future makes a vast improvement. Another thing to consider - if you haven't used vac-form canopies before, they can be a bit tricky to separate from the moulded sheet, and to fit. One slip and it's endex, and if you cut it unevenly, you'll have the Devil's own job getting it to sit square and fit and stick.
It's your choice, but personally I'd stick with the kit stuff, after polishing, for these particular models, and maybe try a vac on a simpler shape canopy later.