I've got the same engine in a Leon. ASV.
Used a Gates kit from a Motor Factors.
There are two slightly different belts, depending on the injectors. A decent Motor factors should know.
Forget Ebay, I've been screwed too many times with "genuine gates" cambelt kits in sellotaped boxes with most of the "genuine gates" bits missing.
Anonymous chinky **** instead.
The AHF engine is basically identical, the link below was very helpful.
Water pump might want to be done too, while your there.
Tedious foul job. Just take your time.
http://www.tdiclub.com/articles/pdf/a4timingbelt.pdf