I have Kalmia 'Minuet' and Daphne x transatlantica 'Summer Ice.' I am somewhat colder than you are and usually Minuet is buried in snow all winter. Even though my larger Kalmias aren't buried totally in snow, they do get good winter shade and so come through the winter with their foliage looking relatively good.

I love my Daphne 'Summer Ice'; delicately variegated leaves, flowers from May through hard freeze that waft scent that most folks find lovely. However, for me here, it sometimes comes through the winter with little or no green left. The wood has been fine for the 5 or more years I have had it, but it isn't particularly attractive right now.

So for me the attraction of the Kalmia is nice evergreen foliage all year and a short but intense set of blooms. The attraction of D. Summer Ice is a delicate beauty all growing season and through the fall and into the early winter, but many years February through April or May it doesn't look too good until the new leaves fill in.

Because you are quite a bit warmer than I am you may find that Summer Ice does better for you in the winter than it does for me. How they look in the winter may also depend on exposure. In general I find that broadleaved evergreens do better in the winter if they don't get too much winter sun, so I try to plant mine where the change in seasonal sun angle gives them some winter shade due to buildings or conifers.

I got Summer Ice from Avant Gardens, but they don't have it listed this season. Lazy S's has it and IME their plants are in one quart pots but well grown and well packed, and grow beautifully.

"I'm looking for 8 bushes, so I don't want to change my mind." Have you considered using a mixed grouping of plants rather than all of one kind? That way, Kalmia foliage and flowers could distract from the Daphne if you have difficult years, and the contrasting foliage color and texture and all season flowers of the Daphne will liven up the summer look of the Kalmia. If you add in a Hydrangea or two and some small conifers, you will have year round interest, both foliage contrast and long season flowers.

Here is a link that might be useful: Lazy S's Farm Nursery