If you are going on to complete the atpl examinations after your ppl then go straight for the crap5. They're damn expensive for what they are, but rumour has it you can pick up second hand ones from e-bay.
As far as headsets are concerned I'd recommend buying a desent pair that'll last you. I use David clark, can't remember the model number but they cost just over £200. They are very good.
Hope this helps.