Get a basket splitter for your KK, that way you can do quick, high temp sears without blowing through a lot of charcoal. It also helps getting to sear temps faster, since it forces all the airflow through the one side. Works great!
It's OK to quick smoke/sear meat BEFORE doing an SV cook, but I wouldn't over do it. The main point of SV is to evenly cook the food to the desired temperature/texture. If you did 90% of the cooking on the KK and just finished it in the SV bath, I think you'd be missing the point, But, I've never done a cook this way, so what do I know?