Hi,
Kevin, having looked at illustrations of Diana the huntress, it seems simple enough, and I understand the choice of subject, nice one !
Greek/mediaeval, skimpy clothing/naked, recurved bow and Dog/ Hart; that's Diana.
But finding one 75mm or bigger,
Phew !
The only suggestion I have is either a large scale fantasy fairy and convert it,
Or something sdimilar.
Morland Studios have a couple of convertable figures, but one is 54mm and the other is 200mm and you still have to get a hound to go with.
http://morlandstudios.com/webstore/index.php?main_page=product_info&cPath=8&products_id=61
Apart from that the only other thing I can think of is a 75mm academy nude to be dressed as you need from el greco.
This is probably not exactly what you are thinking of,
but it may put you on. 'The Right Track' Ha ha.
Good luck,
Paul