encoding question

Hi,

In phpPgAdmin, we automatically set the HTML page encoding to and encoding
that allows us to properly display the encoding of the current postgresql
database.  I have a small problem with SQL_ASCII.  Theoretically (and what
we currently do), we should set page encoding to US-ASCII.  However,
Postgres seems to allow unlauts and all sorts of extra 8 bit data in ASCII
databases, so what encoding should I use.  Is ISO-8859-1 a better choice?
Is SQL_ASCII basically equivalent to the LATIN1 encoding?

My other question is we play around with bytea fields to escape nulls and
chars < 32 and stuff so that when someone browses the table, they get
'\000<unknown>\000...', etc.  However, are the other field types for which
we have to do this?  Can you put nulls and stuff in text/varchar/char
fields?  What about other fields?

Thanks,

Chris