Round or rectangular cooler mash tun?

For no sparge (but not necessarily with a bag), I'd recommend rectangular. Shallower grain beds result in less stuck runoffs. Toilet Braid (or fancy braided hose) works great with rectangular coolers. No need for a false bottom or slotted pipes.

 

Exactly. I'd also recommend rectangular if you're sparging because you'll have a shallower bed as well, especially in a big beer.

 

I use this rather than a toilet braid at the bottom of my mash tun. Cheers!

 

I have a cylindrical mash tun with a single screen across the middle (at the bottom) It more or less reaschs the other side. Cheers!

 

I bought something like this...
https://www.homedepot.com/p/Everbil...r-Coil-Tubing-5-8-in-O-D-1-2-L-10RE/203654558
but not as big or expensive (although prices have gone up! Maybe this is the one but I remember it being like $20), and drilled tiny holes on the bottom side about an 1/8" apart. I pinched off the inside end and then stretched and straightened the other side to come out through the cooler (it fit perfectly through the drain hole without leaking), and I just cover it with a mesh bag while mashing and I've never had any issue with a stuck mash and I always get clear wort pretty much right from the get-go.

 

Yes. When you're batch/no sparging, the length and orientation aren't critical.

 

I e used both and prefer rectangle, especially when make big stouts. Don't have to lift the sparge water as high.

 

A washing machine stainless braided hose, which falls in the category of other fancy braided hose, works well, too. The braided sheath is about twice the diameter of its counterpart for a toilet tank supply hose, and the weave of the braiding (tightness of the mesh) looks the same to me. They don't cost much but you might be able to get one on the cheap(er) by checking with a local used appliance seller or a residential plumber if you know one.