Hi djjjuk, your plan sounds fine - although personally I'd put a few of them straight into your garden to grow so they will increase and you can divide them. Your soil sounds like mine, and if so they will LOVE it!
Paperflowers - I divide mine all year round (I'm not a very organised gardener!) but certainly this time of year would be fine. Dig them up and see if you can gently break them into individual plants - sometimes the roots separate out nicely. But if you find you've got big solid blocks - get tough! Sharp spade (or I often use a sharp carving knife) to cut the clump into pieces, plant again immediately, water them in, wait for next year. Simples.
They are one of my favourite flowers - enjoy yourselves!