Hello,
8k should get you a very nice wagon,
Theres a buying guide somewhere on here can't remember where.
As for buying i'd go for, if it's had mods done id be wanting paperwork same with the ' remap' claim
If they have been done well should have no problems and may be better for fuel economy.
Stantard stuff like reg servicing is a must. Servicing used to be short intervals but newer cars go a bit longer 7k i think. Although most of us change the oil every 4-5k.
Look for one thats had a recent belt change or account for that if it's not been done and due,
Don't be put off by main dealer prices as there are lost of very good independants which will do a better and cheaper job.
I take it your lookong at impreza's ?
I'll let someone else answer the ride question on that one.
I stand corrected but cas registered afer may/june 06 may fall into the £450 tax bracket :O
Anyway welcome and feel free to ask as many questions no matter how trivial or daft they may be.