i'd assume u mean eg9 to mean the model literally. there are a
few models of the civic from the eg series and they come in
different specs and i shall restrict my comments to the eg9
itself.
my honest opinion is that the car would have been "modded" until
like crazy already. it is not difficult for the previous owner to
"unmod" his car prior to selling it. lots of 2nd hand parts from
the car still very much in demand.
car has decent engine (160 hps stock), relatively light (juz over a
ton) and reasonably fuel efficient (when driven with a light foot).
interiorwise, can only seat 4 adults (rear has a center rest that
forbids all but the gay to enjoy sitting on it). excellent handling
coming from the all round double wishbone suspension setup (similar
to F1).
in the end, ur main consideration should be how much of these
original selling points does this car still have? an old car like
that should have seen better days and u would not want to spend on
repairing/ replacing the worn bits of the car.
my advice is to grab a fren who has a keen eye and some relevant
experience with the eg civics and bring him along for a test drive.
it is easy to tell if the engine is in good condition with a
trained ear and a sensitive butt. 
he
should also be able to tell you if the suspension parts are worn by
listening to any sounds that may be produced while driving the
car.
