This is my setup, it's evolved since last spring when I first started doing BIAB.
It's a 20 gallon MegaPot with a 3500w induction heating element. It started as just a large but basic setup, I had trouble with hot spotting in the mash so I added pump. I got really tired of tinkering with insulation, togging the burner on and off, etc to try to hold a steady mash temperature and simply gave up on it about a month ago. I bought a RIMs tube off brewhardware.com and built up a 'Mash Brick' that was posted here on the forums to control it. I'm using a 5000w 240v heating element in it, but I'm only running it with 120v so it's very low density and I haven't seen any evidence on the element that I've scorched anything with it.
For boiling I have a domed lid made out of a large stainless steel mixing bowl with vents cut into the top. With this I can boil 8-10 gallons of water at a fast rolling boil without even using full power on the induction element. Before anyone freaks out about DMS, there's pictures of a similar setup at UC Davis with a dome and basically the same amount of venting as I have. I've had no DMS issues even in beers with high levels of pilsner malt and I'm boiling off around 1 gallon/hr with this so I'm pushing plenty of liquid out of the kettle.
I also have a rather over sized immersion chiller made of 50ft of 5/8" copper tubing, found the tubing for a steal on Craiglist ($1 per foot!). I whirlpool with my pump and a copper whirlpool arm to recirculate and concentrate all the hop material into the center of the chiller coil. I can chill it down to 60 degrees in about 10 minutes or less, but my ground water is pretty cold here in Michigan.
At this point there isn't anything really about it that is bothering me at all. My spray arm on I built into the lid needs to have a clean-out port (grain gets in it and is troublesome to clean out. So I need to add that to it, but otherwise I have no complaints right now.

Mashing with RIMs.

Finished Mash

Raised bag for draining

Boiling

Chill