1990's jap cars were very, very good IMVHO, I've owned 1 Honda and 3 Nissan's and they were all bullet-proof mechanically. Rust is probably the biggest enemy, I would definitely get underneath it and check it out for it, What type of Civic is it a 3 door (EK series I think they were called) or is it the 5 door (MB series) that looks like a Rover 45? I had a 1999 Civic 1.8 VTI-S MB6 cracking car, check for rust though. Rust is what killed my old 1995 K11 Nissan Micra, if it didn't it would of just ran forever. I think the 3 door Civic was built in Japan and the 5 door Rover look-a-like in the UK.
I used to own a 2002 1,6 Ford Focus automatic, cracking car, but the most it would do was 30mpg. It was expensive to tax also but a really nice car.
Edit: I agree with the previous comments about getting a full MOT on the car. Its expensive to get rust damage repaired, I ran my old Micra into the ground, it was 17 years old when it died, but the last few years I was always paying to have a plate put on a sill or the front cross member repaired at MOT time. It made it not that cheap motoring I guess.