Dear all,
I have a novara Randonee touring bicycle. It's amazing but i'm looking into upgrading the rear derailleur/cassette to a more suitable derailleur/cassette for touring.

It comes with a shimano 105 long cage rear derailleur and a 11-28 9 speed SRAM cassette. I'm thinking about putting a shimano XT rear derailleur along with a 11-34 cassette. Any suggestions to which derailleur i should get and why? thank you