27" rims and tyres will be VERY hard to find here - Europe went over to the 700c standard a LONG time ago. Fortunately, tubes are stretchy enough that they are interchangeable between the two sizes. I would say make sure that your bike is setup to take 700c wheels before shipping it over.

No idea how much a chain would cost here because you haven't told us how many rear gears the chain needs to be designed for: 5-speed, 7, 10???

Internet shopping is cheap and easy from the UK and Germany, and prices will be comparable to US online prices. The problem is that Switzerland is not part of the EU, so shipping can sometimes be higher plus you pay import and tax fees on top of your order. But as long as you make a decent-sized order (about 200 CHF or so) then those fees are not so important, and if the order value is really low then you won't pay any extra import fees or taxes. There are now a couple of online Swiss stores who are starting to get a decent inventory and competitive prices, I plan to update one of the original posts on this thread with this info pretty soon. Getting stuff from them is fast and hassle free.

Also, if you're in the Lausanne area then ask me about anything specific you need, I may well have it in a drawer somewhere (e.g., I have two extra pairs of barely-used interruptor/cross brake levers and a pair of aero road brake levers), which I'll sell to you for slightly less than internet prices (plus some old drop bars that you can have for very little).