In reply to beardy mike:
Be interested to know if you find anything. I've done stacks of white water kayaking, but very little in Wales and no pakrafting.
It's very dry at present. Most UK ww needs recent rain
UK ww is generally very rocky.
Pack rafts don't like rocky.
Lower UK river access laws/situation is hopeless
Fish hooks and pack rafts won't mix well.
Bearing the above in mind, not sure it'll work. But would love to be corrected by someone who knows more.