Replication with infrequent large updates

Hi,

I have a couple of queries about replication. Essentially, I have three
servers reasonably remote from each other. The master server gets large
(order 1-10GB) updates very infrequently (every month or so), which
usually go into new schema. The two slaves need to provide read-only
access to these data, and need to continue operating if the
master is offline. Communication between slaves and master should be
secure. IWBNI users could set their passwords on the slaves, but that's
not essential.

Is this sort of use-case going to work straightforwardly with
postgresql9.1's replication (via log shipping), or will I have to use
slony?

Thanks,

Matthew

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Matthew Vernon
Quantitative Veterinary Epidemiologist
Epidemiology Research Unit, SAC Inverness