Nope.. He shouldn't have a devil fruit.
Why?
This world is build in a way so having a devil fruit is both a major advantage and a major disadvantage, and the further we move forward, the less the advantage becomes while the disadvantage is ever persistant.
What makes One Piece a bit genius is that the straw hat crew is build up around the concept that each member is deeply neccesary based on their unique skill none of the others can do.
As it happens, merely having a devil fruit is such a big flaw that going to the ocean alone as a devil fruit user would be asking for death, the devil fruit users on the sunny are all DEEPLY dependent on the none devil fruit users to pull them out of trouble when the disadvantages kicks in.
Remember, sea water not only makes them sink when they fall in... it's bloody kryptonite to devil fruit users AND as shown in Smokers fight against Vergo, against a Haki user using devil fruit powers can become a direct disadvantage in battle on land as well.
The strawhat crew NEEDS it's none devil fruit users... just think about it for a second.
When Brook, Chopper, Nami and Momo was fighting that painter lady... Nami was the ONLY one who could handcuff that woman because she was the only none devil fruit user, none of the others could even touch the handcuffs needed without becoming weak and potentially even faint upon contact.
The idea that devil fruits makes you better and invincible in the world of one piece is a miss direction... it brings as many disadvantages as advantages, and to function as a whole crew where the crew members can pick each other up when they fall short, they need a good number of none devil fruit users to even get by.
As it stands right now, considering just how many DF users there is on the ship in comparison to how many none DF users.. to have any-one eat a DF would become a serious disadvantages to them they don't need.
No matter who it is.. as I see it right now for them, the disadvantages for the group would HIGHLY outran the advantages.
Yup, even if Usopp or Nami ate a devil fruit, I would find it to be a disadvantage to the crew as a hole, they NEED their none devil fruit users.