Aaron Donald is a 3-tech in Kiffin's 4-3 defense every day and twice on Sunday's. He would make a world of difference on our defense with his quickness and the way he penetrates the line of scrimmage. He is as talented a college DT as I've seen in a long time and IMO, the guy would make an immediate impact as a 3-tech for Dallas.
He's so talented and quick that he probably could play DE, but that would be wasting him IMO. You can find guys to get a pass rush from the DE spot and his lack of length would get him stymied against OT's. What is damn near impossible is to get a DT that can put consistent pressure on the QB. Sapp could. Geno Atkins can. Aaron Donald will... and yes he belongs in that conversation.
As for a bigger, thicker guy at SDE... Tyrone Crawford is going to be around 290 and he is a pretty talented guy himself. He can play the strongside End fairly well I bet. Bass is another option there.
We have big bodies for the SDE position. What we don't have is a 3-tech like Sapp that can terrify the QB.
Donald is that guy. Move up if we have to, but if he is close to us we need to get him.
Just my $0.02