A lot depends on what your priorities are for a given model. Are you looking for the ultimate in detail without regard to ease of use? Do you want significant detail with more user friendly bits? Is price no object?
White Ensign Models makes a great set for Hood along with corrected turrets. Gold Medal Models also makes a good set of PE for the basics and a supplementary set for even greater detail. As for quality of materials and ease of installation and reasonableness of price I would go with either of them. Other companies make sets for this ship as well. You can go to WEM's website or GMM's website and see the pictures of the sets. Also try FreeTime Hobbies on the web and go to their accessories section to view the various options.
There are after market gun barrel makers to choose from as well and they can be seen on the FreeTime site.