MLT Recirculating Pump and Manifolds

I want to start improving my mash temps and schedules. I am tired of using the algorithms that always get me a couple of degrees over or under during a step infusion. I use a ten gallon rubbermade beverage cooler with a 1" bazooka type mesh line rigged into a circle. I also use an 8 gallon brew kettle.

I am wanting to build a recirculating system for my mash tun. Not a full blown HERMS system brew sculpture, but just a copper manifold and a slow in-line pump. I figure the manifold would sit inside by kettle and the line would attach to the out barb on the MLT.

A couple of questions:
1. I was thinking about 20' 3/8 copper line. is that going to be long enough?
2. What capacity pump should I be looking at?
3. And where should I look for this pump?
4. Do I need a shower head or should I just let pour over the grist?
5. What kind of plastic tubing should I be using?

1. Probably but I'd use 1/2".
2. The March 809-HS is industry standard for this purpose.
3. Austinhomebrew or .....
4. A showerhead would get clogged in the initial running. Think of all the junk you vorlauf.
5. Thermoplastic or silicone is best. Both can be had at Austinhomebrew. Silicone is a little more expensive but you can see through it a bit.

Bobby is spot on... March 809, Id get silicone from AHS, no on the shower head, anything with small openings will CLOG. I use a 1/2" ID return line.

How is this not a HERMS? You have a coil, right? I dont get that part, but on the other items, listen to Bobby and The Pol...

Not that its not a HERMS it's just not a Fullblown HERMS Brew Sculpture. Just a simple bare bones type of deal.