Guess I don't have a dedicated forum for oaks... but that doesn't mean I don't love them!
I am currently keeping three species of oaks that will do well in Southern California:
Coast live oak (a native)
Valley oak (a native more north in California, but they will grow here if you give them water)
Cork oak (Mediterranean)
If you want quick results fast, go with the valley oak - which just happens to be the largest oak in the world. I am currently defoliating my valley oaks for the second time this summer - they are insanely strong. If you want something that will chunk up fast, go with cork oak - which can give you a 4" caliper trunk in about 5 years.
Which leaves live oak. I won't say it is slow growing. But it has a lot of mysteries. It likes acid soil. It does not like its roots to be touched. It does not like it when you pinch or mess with new growth until it is extended and hardened. In the wild it can tolerate horrible growing conditions... which tends to equate to slow growth. However if you bring them in out of the hot and dry and give them a little TLC, they can be quite robust.
I guess whenever southern live oak comes, up California growers chime in
The Live oak in La. that the OP is using isn't the live oak in California. Very different species.
Southern Live oak (quercus virginiana) is quite fast growing, loves water, but not submerged roots. It grows primarily on the coastal plain from Va. to Texas, with the biggest, most impressive and old trees within 100 miles inland of the coasts of Ga., Fla., Miss, Ala. La. and Texas.
The live oak I have was considered a subspecies of quercus virginiana, but has been re-classified as a mostly separate species. Quecus fusiformis (in my picture) is an upland, more winter hardy and drought tolerant version of the southern live oak. It is hardier and more adaptable to warmer and colder conditions that the European cork oak (and it's equal as a bonsai candidate, IMO.)
It is an extremely common tree in central Texas from Oklahoma down into the Austin hill country. It isn't finicky about soils, both acidic and basic--the soils near Austin overlap limestone, caliche soils (which is basically compacted fossil shell) can have a pH of near 8 or even more. It's a common soil in Texas. Fusiformis has been used as a landscape tree in central Texas for a very long time. It is a "go to" landscape plant and can be found in nurseries all over from seedling size to almost mature sizes in 500 gallon containers. It is even farmed in containers for landscape uses. It is an excellent candidate for bonsai that hasn't been used much.