I'm not sure why you don't think you can source these processors. They're quite common (I see them in lots of designs). Contact your favorite Chinese IC broker and I'm sure he or she can get you it.
A google search turned this up immediately: http://www.aliexpress.com/store/product/the-cheapest-shipping-WHOLESALE-ALLWINNER-A10-IC-BGA-HD-video-processing-chip/700044_731173877.html
You may also be interested in the TQFP version -- the A13 (though it lacks some functionality the BGA version has).