Turbo inlet pipe and y-pipe
 

Where are the best places to get the pipe that goes from behind the MAF to the turbo, under the manifold, and a 45 degree bend that goes from the y-piece on a top mount to the turbo?

Is standard the best or samco/silicone hose?

The STD hose are quite weak and can collapse/leak and are quite restrictive in there design. The samco item is a lot stronger,as well as being less restrictive, so are quite expensive. Worth trying eBay or pistonheads as they do come up occasionally quite cheaply,what model year is your car?

A 1997 uk turbo, will it need a tweak after?

No it shouldn't need a tweak ,as it should only increase bhp by a small amount,it's main advantage is it's strength anda smoother airflow in to the turbo.