Soldato
Go the samples route... simples and free.
Farnell is my first point of call for electrical components, then RS. If neither of those have it, it's probably not worth having/not available from the UK.
Farnell is nice & easy to find what you need too (unlike RS, which is why I go to Farnell first)
Im sorry, but that is complete crap. If you buy no name capacitors, then yes, you get what you pay for.
The problem with Farnell is that it's a minimum order of £20, which is why for thinks like a few 30p capacitors for my monitor eBay has always been better for me.