Hi, I work in Walsall and live just up the road near Cannock. Ricks place is not far from Manchester airport so it's an easy run and well worth it.
Have a look at my build thread, the Mishimoto intercooler is a good upgrade .
BBK aren't that cheap. You could upgrade to S4/S5 calipers on the front and 345mm discs, if you use the rear S4/S5 calipers you will end up with 330mm vented rear discs instead of 300mm solid discs.
I have changed to the Q5 4 pot Brembo calipers recently and these work well again with 345mm discs.
A remap on the standard car will give you around 230bhp I believe, A GTB2260 is good for around 310bhp on a 3.0 TDI so on a 2.7TDI would probably give you something like 270-280 bhp.
With a much bigger turbo Darkside had a 2.7 TDI close to 300bhp
http://www.darksidedevelopments.co.uk/audi-a5-2-7-v6-cr190-cgka/
A 3.0 TDI turbo would be a much better bet though as it's cheaper and better response, plus you have a weak gearbox and only FWD.
AFAIK the GTB1756 and GTB2260 turbo's have the same flange fittings and are a straight swap.