Both are bee-friendly plants, but let me suggest that you get your coneflowers from a neighbor who's dividing, or from a small garden center like Longfellow's. A recent study (.pdf) found that more than 50% of perennials sold at the large retailers like Lowe's and Home Depot had been treated with pesticides called neonicotinoids that make plants poisonous to bees! It's important to note that it was a small sample, and more study is needed; however, I err on the side of caution, since the bees are having a rough go as it is. If you transplant, get a good root ball, and get it in the ground - full sun if possible - as soon as you can.
Echinacea is thought by some to have medicinal properties, including boosting the immune system; this has yet to be proven, and collection of the roots for this purpose, along with habitat loss, has put echinacea on the endangered list in some states.
Coneflowers attract butterflies, and after the flowers pass, goldfinches will perch on the dried seedheads to feed.