As far as the hardy hisbiscus goes Lady Baltimore is my favorite. 6-8″ towers of pink with dark red eyes. This will bloom for about a month (late July-Late August) here in IL. More sun, more moisture the better! Does attract them nasty little Japanese beetles though. So you must have traps to catch them before they get your hisbiscus.
Kopper King: This large flowering red tinted foliage monster is a must have. Reaching a size of 5-6′ with its pale pink, red eyed flowers that bloom from Mid-July till frost seem like they wont ever stop! To have the red foliage, it needs full sun, with plenty of water, and rich organic soil.
Hibiscus Turn of The Century. A taller hibiscus (6-8′) with very interesting 3 toned flowers that tower at the back of your border! Great with miscanthus, and helianthus.