I personally think the 18" ones are better but then im baised...cheaper to buy and cheaper when the tyres need changing.
I got my wheels refurbed in anthracite for £40 each wheel but that was cos I know the lad who did them.
I got the wheels from a company on ebay, here ya go I think he does the 19" aswell but the 18" ones come with the lambo centres which I thought was a nice touch,
[ebay]http://cgi.ebay.co.uk/18-Lambo-Style-Alloy-Wheels-Tyres-VW-Mk5-Golf-Audi_W0QQitemZ280336087408QQihZ018QQcategoryZ9888QQcmdZViewItemQQ_trksidZp1742.m153.l1262[/ebay]
He still uses my pic on his add which I got some free lambo centres for,
Darren