I'd be happy with Jesus if it stacked up financially.
In terms of buying another striker, the way Arsenal's squad is shaping up it seems unlikely we'll play with two up front. If Jesus leaves MC he will want to be starting games, otherwise he may as well just stay there and pickup loads of trophies / money. Therefore there isn't really a scenario where we can buy Jesus plus another striker.
Realistically, Jesus with Martinelli and Nketiah (if he signs a new deal) as backup is what a club of Arsenal's level should be targeting, no point wasting money on loads of strikers who won't play.