I'd agree with all the above, a range of polyleaders is a
must IMHO.
I have the Rio AFS set up and am smitten with it, super-easy to use and on the Don that's a good attribute as the banks and wading can be 'character building' in places
so a quick loading outfit is handy.
Plenty of good rods out there new and used, I wouldn't go above 14ft for the Don.
As has been suggested already, come lower water conditions, a single hander is all you really need - but make sure you've got those polyleaders for that outfit too
Hamish