It's easy if you know how......I've done all the species of larger moth that is here in the Uk and a few migrants also....I didn't find it difficult, well, I should say, i've done harder things....now butterflies, thats really on another level.......to succeed with flutterbyes you've got to become obsessed or you're just wasting your time.......
buy a few pupa for your kids from here: http://www.lba.uk.com/
I will post you a net cage...it's easy, the whole thing is exciting for kids, then (for example) you got elephant HM caterpillars you could rear them on willowherb and then release