The wattage rating on a speaker is all but irrelevant. It tells you very little, because in practice, you will be unlikely to use that kind of power on them. Those numbers are levels at which something in the speaker will fail (x-over or driver). Yes, it does appear they are giving a continuous rating, but I'd still question its relevance.
What I was getting at is, in a typical setup you will only use maybe 5-10 watts to achieve average sound levels. During peaks you may see somewhere in the range of 100 or more watts of demand for a few seconds, so it won't be an issue for a decent receiver, however there are other significant factors as well such as how loud you intend to listen and how big your room is and your room is medium to large.
The S series were some of the best JBLs out there, but yes, they have not been as popular of late. I honestly have not listened to the L series, but the S series were quite good. I would say that the setup you propose sounds fine, though I'd say a comparable setup of the Infinity Primus line might do just as well. Have you already listened to the JBLs?
