Re-routing via third party for certain IPs

I'm now in China, where access to certain websites (most notably N.
American / Europe) is particularly slow. What i'm trying to do in Linux
i'm sure can be done, but I don't know where to start. Anyone know of
any approximate documentation to look into, or have come across some
pre-made utilities for re-routing?

What i'm trying to is, for example, re-route certain URL's / IP''s so
that if I attempt to access them here in China, they will go through an
intermediary server I have in Hong Kong and use the bandwidth from that
machine instead. Ideally I would like to use this beyond HTTP (such as
RSS too), so this would require more than just an nph-proxy. I presume
iproute2 is the way to go? Or has anyone already made a GUI for this
sort of thing?

On a side note, I have already got an nph-proxy working on SSL - but it
can only handle sites, not RSS feeds or similar. Is there an
alternative program which would also work with a non-HTTP based
request?

Thanks,

Terence