You are definitely going for the right look for a foundation planting, namely a layered series of different textures with evergreen at the back. But I agree that a total of 5 feet from foundation out is not enough width to get that job done. You have enough sun to work with and you have a vision, so why not do it up right: expand the bed 3-4 feet, move the roses out a few feet, and then put in some spreading yew or a globe arborvitae-type thing about 2-3 feet out from the house. You'll have to trim the yew or whatever you put there, but it will give you the look you want. Yews are incredibly overplanted on the foundation, but for the back row of a layered planting, I think they work just fine. Put a low layer in front of the roses, maybe some Blue Star Juniper, then you can keep the layered thing going on during the winter. The Blue Star is fairly slow growing, (especially living on the east side), so don't expect it to fill in quickly. Instead, cough up the cash and plant several. If you think widening the bed is daunting, just lay down wet cardboard on the turf and cover with lots of mulch. Then cut out wide holes for your plantings. The grass will be long gone in a year. Boxwood could work against the foundation too, but it grows like molasses. Just my thoughts, based on having been in a similar situation. Get what you want the first time around, so you don't have to do it again later.

Sounds like 'Pride of Houston' is a selected version of Ilex vomitoria (not a hybrid). Foster hollies on the other hand, are hybrids (parents are Ilex opaca and Ilex cassine). One internet source says this about 'Pride of Houston': Pride of Houston can grow in almost any soil and can live in wet or dry, rich or poor soil. Its leaves are narrow, inch-long, toothed, dark green leaves. This Yaupon can get to a height of 15 feet tall and 8 feet wide. Michael Dirr's reference simply says "medium sized shrub with heavy fruit set". HOWEVER, most sources (including Dirr) only list this as hardy to zone 7. If you're in zone 6b, you might be taking a chance on a whole hedge of these should cold temps come along one winter.

Wax myrtle and Yaupon Holly are the first ones that come to mind. If its not too dry, Osmanthus Americanus (Devilwood) may work too. Carolina Cherry Laurel and Yellow Anise are good privacy shrubs too, but im not sure if they'd be poisonous to your dog.

If you are considering Prunus, then I'd focus my attention on a native species, Prunus caroliniana, Carolina cherry laurel. This can grow to a considerable size (much more tree-like than shrubby) but dwarf cultivars are available. I'd also consider Japanese aucuba, Aucuba japonica. Will grow in almost complete shade, very drought tolerant once established and grows rapidly. Other choices would be some of the hollies - Ilex opaca, glabra or crenata - all quite shade tolerant but slow growers. Also Leucothoe fontanesiana (also a native), Pieris japonica, Viburnum davidii, Eleaegnus pungens or one of the taller Sarcococca species. Nandina domestica and mahonia are also possibilities but both have invasive tendencies in your neck of the woods. My second suggestion is to consider a mix of suitable evergreen shrubs. A single species planting invites more disease and pest issues than does a diversified planting and diversification encourages wildlife and offers more visual interest. Wouldn't hurt to throw a few deciduous shade shrubs into the mix also - they will help with the screening (at least during the growing season) and typically offer showier flowering and often fall color as well. And there are LOTS to choose from - Itea, Clethra, Fothergilla, Disanthus, Callicarpa, Kerria, shrub dogwoods, more viburnums, hydrangeas.....etc., etc. btw, plants really do not help with muffling road noise - you need either a significant distance or a solid surface (solid wall or fence) to really accomplish that feat.