1) What are some issues I might run into with the hardpan?
2) How would you store water?
3)Is a pond off the docket?
4) Is it at all necessary to remove rocks from the current soil?
5) Is the best strategy going to be importing soil and making berms and hugelkultur?
6)Are swales an option because of the poor drainage?
I think with heavy equipment you might be able to dig a cystern at the top with or without other earthworks and use it for drip irrigation.