I am looking at a Smoke Vault at my local Home Depot, I am ready to pull the trigger and buy, but I have a few questions: 1. What are the pro's and con's of a 24 inch vs. an 18 inch? (There are only 3 in my family)? Is it worth the extra $100 for bigger one? 2. Approximately how many chips do I use when starting? 3. How often can I expect to replenish the wood chips throughout the smoke> 4, Can I use pellets? 5. How much propane will I use during an average smoke? I realize a lot of the answers to questions are different under different conditions, but approximates are fine. Thanks in advance for your input!!!