An EBJD needs the same size tank as a normal
JD IMO. I have heard they are more peacefull to but that doesn't mean that it is a peacefull fish at all. Just more peacefull than a normal JD is. It is still an american cichlid so that means it will have some level of aggression & you will need to pick tankmates wisely.
Why do you think PFS would kill the fish? For fish that spend a fair amount of thier time digging you are better off having a sand substrate. It is much less likely to cause damage to the fishes mouth & gills. I'm no fan of sand substrates but for digging fish it really is the best choice for the fishes sake.