Dave,

Your solution is probably adequate, but here are a few ideas:

1. if you're running line level audio you may want to run shielded 2-conductor instead of RG-59. The problem with 59 is that you have signal current running through the shield so any stray EMI that's out there will be directly coupled to your audio.

2. I would also suggest spending a little money and ordering cable that is already terminated. Crimpless connectors sound like a good idea, but in practice they can be hard to attach and be the source of all kinds of mysterious problems. Just order cables that are a few feet longer than what you think you need, install them and fuggetaboutit.