http://stores.ebay.co.uk/kando-dynam..._sid=784635164
If you already got a 16T or similar and the exhaust housing is in good nick you could just get a complete cartridge and reused your exhaust housing.
They do a 9 blade option which is supposed to spool around 500rpm faster than the standard 19T.
19T's are not that readily avaliable and usual maintain a decent price so this may be a better option and you will have effectively a new turbo.
They also do just the compressor wheel and housing for around £100 but I would recommend that the cartridge would need balancing after.