Hello all, newbie here!

I live in the Netherlands and I drive a Westfield. SWMBO wants a roof over her head and 5 doors to make taking out the maxicosi from the backseat easier. Now I've seen an advert for a 1999 januari Sirion 1.0 STi with only 10800km(6750miles) on the clock. Costs 4250euro (~2800pounds?) which is quite cheap compared to other sirions over here.
Are there any special things I should be aware of in a Sirion? When does the belt need to be changed for instance? After 7 years with almost no miles I can imaging that certain maintainance has to be done?
Also, I am 100kg and 1.87m tall, will I fit in a car made for small Japanese?

Thanks in advance

Peter Geelhoed