I cannot specifically answer the CLS in manul mode thing, though I would be suspect, as even in maual mode, it is possible that communication flashes could interfere (though i could be wrong). Ideally, I would have a CyberSync transmitter and 3 CyberSync recievers. However, if budget is the bigges concern, a hotshoe adapter for the sync cord, and accessory optical slaves for the SB600's. (see
www.flashzebra.com). Once you upgrade, i would still skip the CLS even if the Bee is connected via sync cord.
TS