"Rare" earth magnets are not rare.And I need one which is easily available, not rare.
"Rare-earth" magnets refer to the "rare-earth" elements used in them, which are not "rare" at all:What type of a magnet is really strong, not too big, durable, and has a long life? Where do I get it?
These two things are about as opposing as you can get... Factor in a few hundred kg of soft iron shielding to your device.it will be lifting quite a lot of weight, More than 30 KG probably(i don't know maybe 60kg!)
And I don't want the permanent magnet to be too strong creating magnetic fields that might interfere in other things.