The An 70 is a turboprop, and the Il is a jet plane. generally the jets is gonna be faster, though, i'm not sure regarding the performance of the props to the heavier Ilyushin.
And regarding the An70 pruchase, I belive its a political 1. Putin managed to merge Ukraine's Aerospace company with russia, and An 70 is part of the deal I belive. Antonov is not geting serious buyers, and they need to make their sales to keep it going.
Next on Russian sights are Naftogaz. I very much doubt Ukraine is gonna be on the opposing end. There would be war if Ukraine tries to join the opposing side. And no NATO country is gonna risk war with Russia trying to get Ukraine, its just too big a price to pay.Ukraine is too significant to Russia's Strategic survival.