We are a startup looking to migrate from Fogbugz/Kiln to a new issue tracker/code review system. We are very happy with Jira, especially the configurability, but we are undecided on a code review tool. We have been trialing Bitbucket, but it doesn't fit our workflow well. Here are the problems we have identified with BB:

1. Comments can be hard to find:
   • when commenting on code not visible in the diff
   • when code that is commented on is later changed
   • viewing the full file doesn't include comments (also doesn't show changes)
   • Viewing comments on individual commits can be a pain
2. We have the implementer merge the diff and close the issue, whereas pull requests are more suited to the open source model where someone with commit rights merges
3. We would like to automate creation of the code review (either from Jira or a command line tool)
4. No syntax highlighting
5. Once the pull request exceeds a certain size, BB won't show the whole thing and you have to view individual commits
6. Linking BB pull requests to Jira issues is a bit janky: we have a pull request URL field on Jira, but this doesn't work when there are changes in multiple repositories

Does anyone have any good suggestion given the above? We are tight on budget, and Jira integration is a big plus. We also have multiple commits per issue, and would like to have the option of viewing individual commits in the review. It might also be worth noting that we have a separate reviewer and tester for each issue.