My current best plan is to mix up a packet of tomato, chilli
and pepper seeds

I would avoid chilly seed like the plague as you have children involved, if
any of them get any of the oil from the chilly - any time from seed inwards_
into their eye then you could really have the book thrown at you.
I would be tempted to stick to something like sweet peas,
Lupins and tree lupins would be an idea but the seed is poisonous.
You don't say how old they are.

--
David Hill
Abacus Nurseries
www.abacus-nurseries.co.uk