Summer childcare

Hi, I have autistic-pathway twins aged 6 and an 8 year old. Am starting to worry about how we’ll cope over the long summer holiday as going out and about with 3 kids with very different needs and interests is getting increasingly difficult. One is a bolter, one often doesn’t cope with new experiences and out mode environments, one is into everything and wants to be out and about.I am starting to wonder about hiring some one to assist me, like an au pair maybe. Would only be short term and would probably assist me rather than a nanny in sole care of the children. They would need to have some experience of neurodivergence etc.

i have no idea where to start or what it is I’m really thinking of/looking for. Does any one have an experience of finding some help and support of this nature? I’d be very grateful for any experiences, tips, pointer etc you can share. 
thanks