Alex,
Bad luck there, however these are quite common faults on the 166which has a high wear rate on suspension components.
For parts, you should try
www.shop4parts.co.uk, or
www.alfaworkshop.co.uk;
The front upper arms, £41, lower arms £94, relatively modest labour costs.
The stub axle bushes probably relate to the rear suspension pillars;
Officially you have to replace the whole pillar, at £220 each, however, there is a thread "166 rear suspension bushes", which relates how you can replace just the bush, at a cost of about £10 each.
You need to clarify this with your specialist, however Sidem part number 49382, or Lemforder 10747 should be the right component.
Springs are about £60/corner from Alfa, however, the improved springs from the facelifted 166
may fit, I am about to attempt this as soon as the parts arrive from Alfa, so I will let you know how I get on.