I've been researching shrubs that do well in full sun. Here are some ideas: Beautyberry; Burkwood Viburnum (or any number of other viburnum); Japanese Kerria; Hardy Hibiscus; Spirea; Pittosporum (evergreen).
I don't actually have experience with any of the above, though they should fit your size requirements and from my research all do well in full sun.

I have winter jasmine..Jasminum nudiflorum..I like it...its a mounding shrub...with yellow flowers, mine stay green all year. only bad thing. when the branches get so long they hit the ground and ROOT!! you can run over them like I do with the mower or trans plant to other spots in the yard.

I'd like to suggest Florida Anise, Illicium floridanum. It's taken four years for mine to get to the size you want, but I started with 2 gal. I think. Love the texture, pale green foliage and 'soft' growing habit.

Rosie, across the state line in Sugar Hill, GA