Jay,
I am a bit late on this thread here but I've just found this forum. Red Tipped Photinia's generally do well here. {I live in the Dallas Fort Worth Area as well.} However, they generally only have about a 2 year life. As far as height we have some to the side of our house tha are taller than the house itself so they can grow quite a bit talle than the 4' that you say yours are now.
I've done a lot of research about something that will flower for yea round here. Thus far I haven't been successful. However there ar several other bushes that can provide an evergreene color year round. There are several types of holly bushes that are evergreen and produc colored berries. The main concern when choosing a flowering bush i the critters that it can and will attract. Not to mention th maintance that flowering bushes require moreso than one that does no flower.
I have acquired many of the items in our yard now from Weston Gardens. It's a little bit of a drive for me Fort Worth. Not sure how far i would be from you. I've found them to be extreemly helpful with an questions and concerns I've had thus far. They have an online websit at
My apologies again if my response is too late to be of any use. If no for the replacement of the current bushes though then maybe you can fin some other items at Weston that would accent and compliment your yard.
His ~angel