I don't have any good pics to share but 2nd Lyndakerfarms opinion on cone flowers. Also have lilies and daylilies, foxtail lilies have foliage similar to thin daylily straps but bloom much later here, late July into late August, depending on the variety. Agastaches and Penstemons are good as well, blooming later and into the fall. Blackberry and Candy lilies are actually in the iris family but bloom well after peonies, have foliage like extra large irises. Spuria iris is supposed to bloom a bit later than peonies, mine haven't bloomed yet as they've only been in place a year.
Peonies are fairly xeric, don't need a ton of water, and some species and hybrids actually seem to resent extra water after they've bloomed. I've had to move some of my Saunder's peonies away from plants that needed more water as it looked like they might've been suffering, also the fernleafs don't seem to like it. Tree peonies, lactifloras and most of the hybrids are fine with summer watering but just be sure you know what you have and try to match watering requirements.
