I have Dubarry's which I think are pretty much the same thing, and I use Oakwood leather dressing - a huge pot cost me £20 and it is brlliant - brings up their colour and protects them too.
Look in Milletts or Blacks for the Nickwax products as they are designed not to damage the waterproof membrane and they do some that will also preserve the suede effect.
Normal products can damage the waterproof/breathable membrane (which is what makes them expensive) or can make the suede go shiney!
I use a can of Traditional Protector £4.95 from Jones the shoe shop on my Dublin Rivers. It keeps them waterproof and is for use on nubuck leather so you dont polish them. They also sell a cleaner for nubuck as well which I use. Has kept them looking good so far!
I used "Mr Jo Jo" a waterproofer/ conditioning was made by Urad (they have an ebay shop). It isn't meant for suede though so the orangey suede panels have gone a lovely chocolatey brown colour and look like leather which I actually prefer!