I think if you are thinking seriously about a cocker spaniel one of the first decisions you need to make is whether you are looking for a show type cocker or a working cocker. This is a breed where the show types and the working types have moved a fair distance from each other. My experiences are second hand but I have a good friend who runs three working cockers. I am sure someone will correct me if I am wrong but the working cockers I have seen are usually a little leggier, their ears aren't as long and their coat isn't usually as thick and they have less feathering. Both types are very active but the working strains will require more stimulation than the show strains. The ear issue is potentially a big issue in a country environment as spaniels ears aren't low maintenance.
The parents of the last litter of working cockers I saw from a breeder I know and trust were PRA, FN and HD tested.
I am sorry but Cockers do have health issues and it is only by testing and not breeding from affected dogs that FN has become less prevalent in the breed.
Having said all of that if you allowed health issues to put you off completely rather than as Doganjo suggests, asking for proof of test results, then you would probably be better off with a budgie - although someone will no doubt tell me that budgies have health issues as well. There are loads of healthy cockers out there both show and working strains. There are three living on this farm, one of whom is a charming little girl who was abandoned after a shoot in Ireland. All three are great dogs, good with stock and with people.
Try these websites - the breed clubs for the two breeds you are thinking about:
http://www.thecockerspanielclub.co.uk/index.htmhttp://www.essc.org.uk/And good luck.