With Christmas coming up, I'm looking to make a major upgrade of my brewing rig. Right now I make 5-gallon extract and partial mash (brew-in-a-bag) brews. For temperature control, all I have is a jury-rigged swamp cooler-ish set-up. My brew pot is 5 gallons, so I can't quite do a full boil. I'm looking to spend about $300-600 to maximize the quality of my brewing. Here's what I've been looking at:
1. Brew-pot. I need something big enough for all-grain, and I may want to eventually move up to 10-gallon batches.
2. Propane burner. I might be able to get enough of a boil using two burners on my stove. However, it may be better to just move to a propane system.
3. Mash tun. I've thought about a DIY project with a cooler. I've also considered going all out and getting something like this with a false bottom. Could it also double as my brew-pot?
4. Wort chiller. How important is this? How much would I save building it myself?
5. Refrigeration system. It would be nice to be able to do lagers. What would I need to buy?
So, considering all of the above and my price range, what will get me the maximum bang for my buck? Any advice? Thanks.