Aho's likely not available. Barkov is definitely not available.
Tom Dundon (owner of the Canes) said that Aho was completely untouchable as he personifies the new culture they are trying to build with the Canes. So Aho is definitely not available even for a vast overpayment. Not sure what has been said about Barkov, I assume similar sentiments.
I agree that Aho is a hell of a player, but Barkov does more. Plus he's on a cap friendly contract. I would take Barkov everyday over Aho (not that I wouldn't want Aho also).
Hard to compare the two directly when Aho is 2 years younger. Obviously Barkov is better now, but Barkov didn't break out till his 3rd year in the league. Aho just finished his 2nd with 65 points. Granted, D+1 (Barkov) vs D+2 (Aho).
As far as "doing more", both players get a TON of work done. General Finland fans can attest to that if they watched Aho at the World Championships this year vs Barkov in the past. PP, PK, and ES domination.