Welcome to the forum Stuart, you'll find the members on here are a friendly and helpful bunch. Did the car come with full/part service history?
I ask as the history of the car may help in deciding what may/may not need doing.
First thing I would be looking bat is when a full service was carried out along with then the cambelt and water pump was last changed.
Injectors are a known weakness on this engine but I personally wouldn't change them untill they fail.
Also it's worth checking turbo boost hoses, radiator hoses etc for any splits.
You can get oil pump drive problems with this engine. The oil pump is driven off the balancer shaft unit by a hexagonal shaft (imagine a 6mm allen key with the 'bent' end cut off), which can wear smooth. This problem is quite rare though, and you dont have to expensively replace a substantial part of the engine to repair it. There are upgraded balancer what's available. Cost:
"Only prob with going this route is weather to change the oil pump and sprocket at the same time, further cost of circa 300 quid for parts alone."
Wing mirrors have probably been painted silver to give an rs4 look. You could changee the caps to blue but it's personal preference really.
also if you're trying to find what options your came with when new there is a build sticker in the spare wheel well and in the inside front t page if the service book which gives all the codes. Here's a decoder to help you find what options your car has:
http://prsearch.planetvag.com
Hope I've helped 🙂
Cheers
Steve