Thanks again everyone. The middle bed is filling in now and there are some irises blooming. More pics to come.
Jackierenette, If you get the doublefile, you might have to be really patient. I love it now but it took about four or five seasons to really bloom. The first several years, there were no blooms. Then another year, it got just a few. Now it really is in it's glory but it took soooo long.
Now if you get spirea, it should bloom the first year and they are so hearty. I even dug one up because I was rearranging things, left it just sitting there, and it grew roots into the ground and bloomed this spring.
I'd go for the spirea because you'll get blooms the first season. The viburnum gets to be about 12 ft tall too, so it might be too big. I also have clay. My viburnum gets late afternoon sun for a few hours a day. The spirea, I have two, and have moved them both several times to different spots and they seem to be happy anywhere. Weigela might be nice too if you want pink flowers.
I just cut back my spirea today. My biggest one. I cut off between 1/2 -2/3s of it. It was about 6' tall and 8' wide and hanging so that it blocked my view of some of my other beds and was in the way of mowing. Got 2 more big ones to cut back tomorrow...so give them plenty of room! And mine only get water when it rains and they do fine whether we have rain or drought. But they do get aphids every year on new growth. I just squirt them with the hose several times to get rid of them.
"The soil is the source of life, creativity, culture and real independence." David Ben-Gurion