need recomendation on small flowering shrub for zone 4 (MN)...?

our bed has some boxwood, hydreangas, birch tree, and we had 3 small shrub roses , but the japaneese beetles destroyed them, so we want to repace them whith something else.

criteria must be:

grow no taller that 2ft (maybe we will stretch to 3ft, ut really wabnt small so these down ovr shawdow rest of the bed.

flower must be white, pink,. or red

prefer bloom last a little while (unlike peonise which only last a few weeks)

must like sun

any help would be greatr