Four thoughts for your system design. 1) Keep your MLT on the lower tier as planned to make for an easier mash-in. 2) It looks like you are planning on running your sparged wort into the valve of the boil kettle. Once you get a few gallons into the pot, you won't have a way to watch and regulate your sparge speed. I'd suggest pumping through a tube into the top of the kettle. That way you can pick up the tube and see your flow rate. 3) As a future update, you could easily build a HERMS coil that sits in the HLT and use the pump to recirculate your mash and regulate temps (cuts out the need for a burner under the mash tun except for initial heat up. 4) Whatever you decide, enjoy the building process and your first beers that come from it!!
