I started out too doing extracts, and was very pleased with the end product. I moved to partial grain, then onto all grain. If you're thinking of moving to all grain, then the sooner the better.
I moved outside with a Banjo burner and converted two sankie kegs for brewing. One thing that I realized was that while I was "upgrading" my system was always in a state of change. I never did two batches the same.
Now, my system is dialed in, my equipment is up to the task, and I'm getting into a rhythm on brew days that has resulted in less stress, more fun, and a better product.
So, build a large Mash Tun from a cooler, I use a 48 qt Igloo cooler with a 3/4" SS braided filter. Works for me.
Get a BIG brew pot, or convert a keg. Full boils is the way to go. Get a burner that can handle a keg and get at least 7.5 gallons up to a boil in a fairly short time.
It's a Hoot. Good Luck...
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