I would suggest Shop4Parts if they have them, they are the favourite supplier across the forum, also if you
donate to the forum you'll get 10% off the whole order & also discount codes for other Fiat suppliers for members who have
donated. Here are a list of suppliers that do Cento parts that I've used,
1) Shop4Parts (10% off every order for
donated members)
2) Italiparts - a supplier of genuine new old stock & obsolete parts for Fiat's, Alfa's etc with very quick delivery as I had to recently order parts for my Seicento.
3) Ricambio - a firm in Wallington, Surrey who do most Fiat parts including Cento's.
4) Main Fiat dealers themselves - I've had to resort to main dealers a couple of times since owning my Seicento as a few spares are now getting a little thin on the ground, you might be surprised though as sometimes they can be cheaper than pattern parts, like the exhaust on my Seicento will possibly need replacing soon from the cat back as it has a very slight blow, being an 899cc though not many suppliers are doing the exhaust for them anymore, hence it's cheaper to buy it from Fiat than aftermarket suppliers.
For bushes etc I would stick with standard OEM spec or equivalent parts as I've had experience with poly bushes & wasn't a fan as it made things too stiff.
Also I've just had a thought regarding the rear wishbone bushes, unless they're making a knocking/bonking noise when driving along (a known trait of Cento's) then personally I would leave them well alone until they really need doing as this could open up a can of worms & be a real headache as the bolts never come undone without snapping even after being dowsed in penetrating fluid which usually results in having to cut the bolts with a hacksaw as the bolt seizes in the metal sleeve on the bush, then once the bolts out the bush itself will be reluctant to come out as it seizes to the arm so usually have to get a little creative or use heat to get the bush out, if I had to do these bushes on mine from experience & to make life a hell of a lot easier I would spend a bit more & just buy the whole new arm with the bushes pre installed (I remember the 3 day hell from my old Cinquecento when I was 17) & then lube the bolts up with a good helping of copper slip or even better consider using stainless bolts.
Also if you add your car details in your profile & in the members garage like chassis no, reg no etc only you can see them yourself it's not made public, when your logged into the forum go to
Eper, then click on my vehicles & it will come up with your car details, click on it & it's basically a parts diagram for your specific car so if you need parts it's all in different section such as engine, suspension etc & it has every part number for every part of your car, it'll also tell you your car details from the factory from the chassis number such as build date, model spec, interior code etc it's truly a fantastic bit of kit, it really helps as well with getting the hard to find parts for a Cento or any other classic Fiat as from the part number it'll tell you whether it can be ordered from Fiat or not, also if your browsing on eBay & someone has a new old stock part listed with a part number & no other description on the listing as the seller possibly doesn't know what it's for, you can look the part number up on
Eper & possibly get a bargain if it's for your car