How about something evergreen and also something that flowers in the summer. I would plant Hypericum calycinum - St. Johns Wort.

It's the right idea, but i'm in zone 4A at best, and more realistically 3b... i think it would probably die.

It's also going to go around a bunch of spireas and a lilac bush - so the lower to the ground and the more "creepy" the better. :)

Here is a link that might be useful: {{gwi:27053}}

If you want low to the ground, you could do a mixture of ajuga and sedum. Ajuga can get in the lawn if it loves your property, but sedums rarely would. They can both handle your full sun.

Regarding the junipers, I'm not sure that they would really "grow around" the spireas. I think they'd eventually end up competing and overcrowding each other.