need suggestion for server sizing

Hi all,

I need your help to determine the configuration of a server machine, and the
PG DBMS.
There will be not more than 25 concurrent users. They will use a business
software that accesses tha database. The database will be not that large, it
seems that none of the tables's recordcount will exceed 1-2 million, but
there will be a lot of small (<5000 record) tables. The numbert of tables
will be about 300. What server would you install to such a site to make the
database respond quickly in any case?
I would like to leave fsync on.
Perhaps you need some additional information. In this case just indicate it.

Thanks in advance,
Otto