I use a Magma Master Caster and it is a very good unit. I also use a Lyman #20 pot and a Rapine #20 pot. The Magma is fine when I am doing a lot of casting but if I was to do it all over again I would be using two Rapine pots side by side in order to do a lot of casting. I like hand casting over casting from a spout and I do not like putting lead into a pot I am casting from. The temperature controls on my Rapine are extremely accurate. I use a thermometer to check temperature, so I know which pots are the most accurate and which ones come up to temperature fastest. I would be casting from one pot and adding the sprues to the second pot. When I emptied the first pot the second would be up to temperature and ready to go. I would keep the process up like this until I was done casting. Of course I would have to add some lead to the sprue pot in order to keep it filled and ready to go but this would be done as I am adding sprues. The Rapine pot has a stainless steel outer case and is very well made but it is strictly for hand casting and it is a #20 unit.
None of these units, Magma, Lyman or Rapine are inexpensive, Magma probably being the most expensive but it is the largest.