Hello there,
Poor you.
I can't really offer you any real advice I'm afraid (none of us really can over the internet), you really do need a qualified behaviourist to meet you and your dogs and asses what's going on. Neutering one or both dogs may help, but is no guarantee that it will alter the triggers that are causing the attacks. There are a couple of behaviourists on this site and hopefully one of them may be able to recommend someone closer to you that can help you.
Just so you know though (although I'm sure you already do I've probably just misinterpreted the way your post is written!), the pure bred cocker isn't behaving in the way he is because he is a pure bred. Pedigree dogs have received a lot of bad press recently but there are 1000's and 1000's of lovely pure bred dogs that don't have behavioural issues just as there are lots of cross breeds that do have problems also.
Hopefully someone will be along with a recommendation for you to contact shortly, best of luck with them.
Hannah x