Wow- you're starting off thinking about a kit I wished I would have chosen! I started smaller, but had to buy more items to get what I needed.
For a propane burner, there are some around here who use turkey fryers. I'm not sure how they work- but someone else will chime in and let you know.
If you are doing partial boils (how most people start out), a smaller pot is fine. You may have one laying around- I use my canning pot. But for All grain or a full boil, you need a much larger pot, I'd say 40 quarts. You want something that is durable and won't scorch on the bottom. Quality is important in this case.
Any questions you have are always welcome.