Hi
and Welcome to the Garden Helper
You mentioned this area is on the south side that gets full sun. Hosta's are a shade loving plant,, so Not a good idea to plant them there,, Hosta's do well under full trees,, or under awnings, where ever there is plenty of shade,
lily's will do well in full sun,, You also need to know
lily's will spread over time IN a few years that area will be full,( depending how many you plant now, Since they are the taller plant they would be better placed in the back row,
What would be nice planted in front of them are
flowers that have a long blooming period so when the
lily's bloom's are gone you'll still have something blooming
or at least something with very nice foliage ,
Vinca's , cone
flowers, Campanulaceae (The Bellflower Family) asters, blanket
flowers, are long bloomers,, There are many members here that are in your same planting
zone, that would have a better answer as to what to plant in full sun that would come back every year. I just wanted to make you aware that Hosta's are for shade.
You could also Look up native plants for your area,, so you could have a better idea which ones loves full sun,, blooming periods,, Height,, etc,