I would e-mail or call Catoma Outdoors first. Most companies sell replacement poles, or will tell you where they can be repaired.
This is just my thinking on a "spare" tent: Tents do not usually fail suddenly in normal use. If your main tent starts to show signs of failure (wear and tear), there is usually time to get a replacement. A spare tent is just something else to store.
Another thought: Have you considered a 2 person tent? It sounds like your tent is your home. It seems that a 2 person tent would give you a little more space to "spread out". You can get a nice 2 person tent that is lighter and more roomy for about the same price. Just a thought
Get it from REI; they have a great 1-year replacement policy.