Traffic Shaping for a Newbie

Hello everyone,
I hope it doesn't count as crossposting when asking in the mailinglist
and in the forum. I just figured, the mailinglist seems much more alive
:)

I'm pretty new to m0n0wall and I'm looking for a good solution for a)
logging and b) traffic shaping. I have several traffic shaping pipes
set up and running, but here is the problem: The rules are usually set
to "single host" or a certain IP, since I use managable
switches/routers as clients. Behind each client exist all kind of
traffic. With the existing rules I just make sure everybody gets a
certain maximum of the WAN connection, that works fine so far. But now
I want prioritization of VOIP within that pipe.
To be honest, I'm not really sure if I need that at all if the client
host=switch/router can already prioritize the traffic from his
subnet...

I already found some information that something like a pipe within a
pipe (I think that's what I want, right?) is not possible. Alternativly
I could prioritize VOIP traffic generally, but that wouldn't be my
favorite solution.
Any ideas?