Take a look at P4Merge for doing your merges/diffs - it's a very nice tool for merging. You don't need the entire P4 ecosystem, the merge tool is standalone.
hear hear! I've been using P4Merge for years since it's indeed very nice, also have it set as 'external difftool' in ST. Only disadavantge for me: line ending settings for the merged file are fixed, which is messy if you have repositories from different sources and/or different autocrlf settings
