Iron doors are really beautiful but unless you find a real deal you are probably going to end up paying between $2000 - $5000 for them. I have never really seen them for much less. They are relatively labor intensive to make
You may simply have to use a more powerful chemical stripper to remove the sealant. There is also a method where a sheat is laid over the concrete and soaked in stripper, then allowed to dry. This should allow you to lift the dried sealer right off of the floor