In my experience, I had configured a warm standby for 2 TB Postgres Cluster (PostgreSQL 8.4).
Note : I do not know your database size and WAL archive generation rate.
Important considerations i made were as follows -
1. WAL archives transfer from production to standy depends on the network bandwidth (i think you said there is no issue there) and the size of the
WAL archives.
2. Transfer rate can be optimized by compressing the WAL files. Each WAL file size would reduce to 2 - 3 MB from 16 MB (only in case of warm
standby. In streaming replication size would decrease to 7 or 6 MB), which makes huge difference for the network bandwidth.
Compress the WAL archives at the production and transfer & uncompress the WALs on standby.
I did this successfully.
Hope this helps !
Thanks