a 1995 will be whats known as a 'classic' shaped imprezza, they ran all the way up to 2000 with some minor styling changes. post 1997 the interior was update and personaly i think its a big styling improvement on the earlier interior (but thats a personal preferance).
A few things to bear in mind,
1. when it comes to running costs, they are a £30k performance car, even if you buy it for £5000. Regular oil changes (3-5k miles depending on how its driven) is a must.
2. They are old, even the newest will be 22 years old, so wear and tear, rust etc will be present no matter what. Unless you spend 25k on one thats had a bare shell nut bolt up rebuild.
3. Beware cars being sold that arn't what they claim. Any turbo charged uk classic will be a uk turbo or turbo 2000, wrx and sti's were import only at that age. They were all 2.0 turbo (well bar the 22b, but you dont need to worry about that unless you have £250k to spend lol)
4. special editions were mainly just special paints and badges at that age.
hopefully gives a few usefull bits of info for you 🙂