Help!

In the midst of yet more packing today, C called me into the garden. We have one very pretty pink shrub that was absolutely covered with bees and butterflies. This Red Admiral is enjoying a real feast. 
Unfortunately we can't find a label on it, but a bit of research makes me think that it's Spiraea Japonica and possibly either Genpei or Sparkling Champagne. Can anyone (Paola??) possibly identify it? It's currently about 1.5 m high with a spread of around 1 metre.
We'd love to plant one (or twenty!) in our new garden. 
I've put in an extra also, showing a bit more of the plant (plus a Tortoiseshell).