So, it's "do as I say, not as I do," huh?So you’re into overkill? Here, here! All of my XLR cables for my microphone and preamp are Mogami Gold and I’ve used their stuff for DIY RCAs. Good stuff. And I usually go much larger than necessary and do like the OP to strip a little wire if needed to get it to fit.
I'm with you and Holmz in the overkill department.Really, why use 14 vs say 18? The size should be chosen based on length and power being used. Longer runs with more power need larger gauge wire and shorter runs with less power need less. So based on the limited information, I have no idea what you should do. If your crossover is close to your amp in the back, you might be able to actually use a smaller wire and you actually need larger wire to get to your speakers because they’re way up in the front. But in general I would think 16 gauge or even 18 gauge would be just fine for most installs.