What kind of equipment do you have?
It's a far cry from what BIAB brewers originally used to sophisticated gear like the Brew Easy
If we start with the idea that all you need is a heat source, a kettle and a bag, then I say we are in KISS-land. You may then move slightly out of it - if you feel the need - by adding a tap and a false bottom. That allows you to do batch sparging very comfortably; you just drain the kettle into a bucket and add the sparge water after that. Of course you then need some means of heating enough sparge water, but sparge water actually need not be very hot, so you can get by by just boiling up some on your stove and mix with cold water in a bucket. Get it up to 90 F and you're fine.
That's basically what I have been brewing on for some years, and I am totally happy with it. (I won't lie: I've added several kettles of different sizes and a couple of heavy induction plates, so I can't claim I'm all that much of a puritan. But no pumps and no electronic temperature control