network protocol and compatibility question

Hi All,

We have been running our product on PostgreSQL for quite some time now.
Started out with 7.0

I have this situation where i want to migrate my (many) PostgreSQL 8.3
databases to a new server running 9.2
In my case this is not a problem for schema and data.
But i do not want to update the client's drivers if i don't need to
right now, but prefer to do that in future updates.

Reason is we are moving to new server infrastructure and want to go 9.2,
but the 3rd party making the database driver for our legacy product has
issues.
This will otherwise keep us from moving to better/supported version.
(insert legacy headache here)

I found that the pgsql network protocol spec has not changed between 8.3
and 9.2.

Can i use my 8.3 clients on 9.2 servers since the protocol has not
changed and the database schema remains the same?
I would think yes, i will test but it would be best if backed by some
kind of theorethical rationale.

Any alternatives?
Can i put pgBouncer 9.2 in front of a 8.3 server for example?

Thanks in advance for looking at this issue.