There is an oak that I have simply fallen in love with and think might be perfect for your described space. It is the Crimson Spire Oak. The only thing that would worry me about planting a row of oaks though is the root fungus killing oaks that is spreading from California and other places. Lots of beautiful and majestic oaks have died from that fungus. I do not know if the Crimson Spire can resist that root fungus.

The Natchez Crape Myrtles grow up to 30 to 40 feet tall and sometines a little higher if grown as a single trunk tree. If you plant them, space them properly for the tree's mature single trunk canopy width. Also make certain to plant ones which have already grown to at least 8-10 feet tall, and keep pruned away lower branches which might grow low enough to cause problems for people and vehicles on the driveway.

You could also plant some rose bushes beneath and between the crape myrtle trunks. Then years later if the Crape Myrtle canopy gets to dense and restricts the roses from getting enough light to bloom well, just transplant the roses to a sunnier spot, and put in shrubs which bloom well in the amount of shade that the Canopy creates. If your Crapes go dormant in the winter, it would also be nice to instead plant some appropriate featured evergreen shrubs under and between the Crape Myrtle trunks. I really like Yaupon 'Nana' holly leaf texture for growing under Tuskorora Crape Myrtles, which have reached 10 feet tall. Your Natchez trees most likely would need a shrub that grows a little taller. than that. My friend has some 'Carol Mackie' Burkwoodi Daphnes planted in a raised bed under some of her Muskogee crape myrtles and they look very good with those newly planted nine feet tall crapes.

Then again there are some Plum yews which can take more heat and will grow in zone 8. If you select a plum yew get a cultivar which will not grow above the desired height and does not spread so far that it spreads onto your driveway.

I also have 2 BBB planted here. The smallest one blooms from late May until early July. The largest one blooms from mid May until late July here. Although it's only about 15' tall and I've seen larger ones in Oklahoma(zone 7) which bloomed from early May until late July. So, as they get larger they have more blooms over a longer period of time. Also, the old saying about the darker brown back of the leaf, the more cold tolerant is a myth. Very winter hardy cultivars like '24 below'(it's never had any leaf browning in the winter here, after about 15 years) have virtually no brown indumentum on the leaf undersides(ie. they're mostly green on the leaf underside). While BBB does indeed have a rather dark brown leaf it suffers more from leaf burning in the winter than many cultivars with much less of a dark leaf back('Tulsa', '24 Below', 'Edith Bogue' to name a few). It's perfectly wood hardy though (in my area). Actually, in my opinion BBB suffers more general leaf burning in winters here than virtually any other cultivar I grow, even though like I said it is completely wood hardy and only the South and West facing leaves(most exposure to winter sun) have significant leaf burning in cold winters.

I tried to give an idea of how these trees perform for me, and how they have performed in other areas I've observed them, but how they perform in your area will probably be a little different. This is because of differences in climate, latitude, etc.