many thanks to all for your advice!

finally managed to get in touch with a rescue centre - we're going to see some ferrets tomorrow, with a view to 'reserving' a couple for when the cage arrives (I've ordered the one on the right in the OP)

Will have to think hard about whether we can handle a pair of kits. If it's just about a few cuts here & there, that's OK, but it sounds like there's a lot more to it than that!

Anyway, will keep you all posted, & thanks again!