Don't know any US or Aus suppliers, but here's my collection:
UK sellers
Euro Car Parts and
Halfords each have a modest selection. Below are the special sellers based in the UK. They obviously have the advantage of delivering parts to you quicker.
sunriserpht on eBay
LP Garage is located in Suffolk. They stock 126 parts and I'd trust them to work on my 126 if I lived near them! The sell stuff using eBay, their username is sunriserpht.
Ricambio
Classic Italian car parts shop based in Surrey, has a bit of a reputation for being costly.
European sellers
Delivery might be a little longer, but these places are good!
126 Fan
126 specialist based in Slovakia, probably the cheapest place to get parts outside of Poland!
Axel Gerstl
126 specialist based in Germany, comprehensive and impressive catalog of parts.
Other 126 part sellers in Europe, worth a look when searching for parts:
F.D. Ricambi
Gunter Markhof
Fiat Fischer
Partacus - you need to know the part number
Polish sellers
Probably due to it's heritage, the 126 has lots of parts for great prices in Poland, which is why I've given Polish sellers their own category! The only downside is the sites don't have an English language version, so having Google Translate open as well helps.
Regmot
Polish car parts shop that has a lot of 126 parts at low prices. Particularly good if you know the part number, you can just type it into the search box to find it.
Motozbyt
Another Polish car parts shop that has a good selection of 126 parts.
Allegro.pl
Allegro is the Polish ebay, and is probably the cheapest place in the world to get parts. The downside is Google Translate doesn't work on the site, so when you're browsing it you have to copy and paste words into Google Translate to see what they mean. You may also find it difficult to find what you're looking for if you don't know the Polish technical term for a car part. However if you have the patience, it's a great resource.
