is it possible to grow teak from seed in this country?

I wouldn't of thought so as its a tropical gardwood. Unless you have a huge conservatory that doesn't get cold in winter.
Loamy/sandy soils, damp and acid pH 4.5-5.5.

I can't imagine its a very feasable thing to do here in england!

You would be growing for future generations then, Archie?

You will need a fairly large conservatory. Go for something 40 to 50 metres high as this is how tall teak trees grow.

And if you want to see the finished article you need to be no more than about 6 years old :-))

Planning for a conservatory may be an issue...