Aha! This question is the source of much debate and friendly ( ) banter!
Quality Japanese wheels will cost you anywhere between £1500 and £3000 from an English supplier. However, suppliers in the UK are a bit limited so now is a good time to take advantage of that exchange rate and buy from the US where you'll save a packet.
There are other wheels available which personally I have no problem with but others do, such as TSW, which I think you can source over here for less than £1k.
Is your priority looks or handling? Cheaper wheels will be cast and therefore will be heavier than stock in a 19 or 20". Do you mind importing or do you want a UK supplier?