I have a hockey game to attend this evening and we're hosting our game companion and another guest for the evening, so I won't be online until very late this evening. I can quickly clone the Porygon-Z, however, and have it ready when I go on.
If you're here, oh, nine hours from now (1:57 p.m. EST, see timestamp top-right), I suspect I'll be around after that. At the earliest, eight hours, but no guarantees.
I don't know offhand what nature it is, but I've already done trading between my two games to evolve a cloned DW Porygon to its Porygon-Z form. Thus, I have a Dream World Porygon-Z that I clone and share. If you're interested, I can just send that to you.
If you don't like its nature, I can try to breed another one. Mebbe. May not be DW ability however.