I think I would wait until after they bloom.

amberroses is referring to the fact that camellias are starting to develop flower buds now and you may miss the bloomage if you transplant now. Plants that are moved will usually suffer from transplant shock and existing flower buds may be aborted during these stressful times. Depending on the type and variety, camellias can start in Sept-Oct & bloom well into March of next 2010 (or a little after that). The previous owner might be able to give you more accurate blooming times.

Your success rate may be better if you do this while the plants are dormant, i.e., when Fall-Winter arrive and not while Summer is going strong. Choose a location that protects them from the hot afternoon summer sun. For example, select a spot that gets shaded at the same time as the current one does or gets shade starting around 11am-12pm. The sasanqua leaves will handle more sun than japonicas leaves do so keep that in mind too. The new location should be mulched with 3-4 of mulch and should have a sprinkler/drip system that can provide as much moisture as the existing location.

Here is a link that might be useful: Camellia Information by the A. C. S.

If you are still in touch with the previous owner, it would be extremely thoughtful if you contacted him and asked if he would like to come (in the late fall or winter) and take a few. Since you don't seem to particularly care, I mean.

He might even give you some tips about transplanting so that you have some chance of success.

Or see if members of a local camellia chapter would be interested (you do not indicate where you live so I cannot recommend any ACS Chapter but you can look in their website.