Not to mention what shades of pink are you looking for? You can go with the softer pinks (New Dawn
http://www.helpmefind.com/rose... this is a climber, but using this only as a color reference) all the way to a hot pink (Hot Princess
http://www.helpmefind.com/rose...). Height, width, once-blooming/all seasonal, floribunda/hybrid tea/grandiflora/OGR, scent, cut flower quality, etc etc etc If you're looking for white/pink, so you want roses that start off white & fade to pink, roses that are white & pink already, pink roses that fade to white...
And
w/Zuzu.. why stick 4 in that huge of space when you can have 40? Seriously! My front yard, which is microscopic (about 15' wide at the narrowest, 30' wide at the widest, and about 80' long (I live on a pie-wedge-shaped property)) I have over 90 roses in the front with still tons of room for them to spread out. And that also includes a number of other shrubs and a tri-color beech tree, too. Roses get along quite well with trees believe it or not.