Updating version on Debian Etch (4.0)

I have nginx 0.5.32 running on a very busy server under Debian Etch. I’d
like to update this at least to version 0.6.35 (which I have running on
another server, under Ubuntu 9.04), and I’d like to make the update
process as undisruptive as possible, with minimal downtime. I want to
maintain the layout of conf files, logs, etc. Is there some way I can
use the .deb package from Lenny, or do I have to build from source? Any
suggestions on smoothing the path would be most welcome.