1 - is Caron Collection Waterlilies thread, it's a 12 strand SILK thread, that's why the price is so high.
2 - you can get DMC pearl cotton at any craft box store, it comes in a small ball like yarn sort of. If you don't have a Michaels or JoAnns or store like that near you 123stitch.com on-line carries it.

Hope that helps even though I'm not Kristi, I believe they are off on Sundays.

Marlene,
Hello. I am currently working on this piece. I'll try to answer your questions.
First, the Water lilies, is a silk thread, (the reason the price is higher). It is a very soft, very pastel verigated floss. You could replace it with a verigated DMC floss, that is similar in color, which is a soft blue, green, pink, & lavender.
If you would rather not use the Perle cotton, replace it with one more strand of floss than what you use on your regular cross stitching. So, if you use two strands for your project, use three strands of floss for where it states using the perle cotton.
Stoney Creek uses lots of different methods to create a different effects with their patterns. I have stitched a lot of them over the years. They all turn out beautiful.
I think that if you change the pattern to something like I suggested, it will have similar results.
Hope this helps.
Nita

Thanks for the help ladies! You're great!
Where are you getting "water lilies" from? It's says "storm clouds" clearly on the supply list? I'm confused............

Marlene,
Waterliles is the series of silk floss from the Caron Collection. (A trademark) The color is Storm clouds.
Caron Collection has a couple of different types of floss, each with a lot of colors.
One is Water Colours & the other is Waterliles
Hope that clears it up.
Nita