Just avoid the no-name ones on ebay, the balljoints are made of toffee.
Interesting point. On our other car, Astra, Ive just replaced the NSF drop link. The brand was "Key Parts", whoever they are, and came in a nice orange branded box at a cost of just £6.39 delivered. I have no idea how long it will last, but it felt well made as far as I could determine and has stopped the clonking noise.
Check out eBay item number: 233732383794 - change out of £10 for a Jazz drop link
Keyparts - Firstline - Borg & Beck are all the same parts, they are at the cheap end of the market, but seem fine - I've fitted quite a few Firstline parts over the years, a local motor factor supplied them until they closed down. Don't get too excited by the "Borg & Beck" name though, Firstline only bought the brand name.
I bought a pair of B&B droplinks for the old Jazz, I think they worked out around £16 for the pair, cheapest branded parts I could find at the time... one fitted seems to be holding up fine.
When I say "no-name", I mean the anonymous or sometimes supplier-branded ones that are sold on ebay and come in clear plastic bags. I don't know where they come from, but they really are junk.