Companion plants for annual vincas?

Hi all, happy (almost) Friday! I'm wondering about good companion plants for upright Vinca annuals for container planting. I'm on a heavily shaded, humid patio in zone 10A (though I've managed to get one corner that has a few hours of morning sun). Any suggestions? I also have wax begonia seedlings, but I think their watering needs and size to which they'll grow might not make them a good pairing?

Any recommendations would be greatly appreciated!

Shown below: the vinca seedlings I have.

 

Hi there ! Those look larger than what I am used to !

 

Hiya! It's probably because the image size is so big I had the camera really close! Each one is only about 5 or 6 inches tall.

 

i think some miniature zinnia would look good !! but that depends on how much sun in that area !

 

Impatiens would be a good complement for them. Plus they like shade. Just be sure is the shade loving impatiens. Happy gardening.