A place where I throw links that you might find useful!
http://www.bitsbox.co.uk/ …in the UK sell a wide range of components, including Alpha 9mm pots used in a bunch of FC projects
http://www.ginkosynthese.com/ …a great range of DIY and ready build Eurorack cases. Also home to the superb Sampleslicer module
http://www.futuresoundsystems.co.uk/ …modules, accessories, Eurorack ribbon cable etc…
http://www.lamonddesign.co.uk/ …bespoke wooden modular case – best in the business…!
http://www.synthracks.co.uk/ …some great looking cases here!