Yes you will need Merkava sprockets as well. Modifying the AFV Club sprocket hubs might need some careful thinking and planning. I have done it on an AFV Club M60 to add Merkava tracks but I need to check the M88 kit hubs if it can be done.
Tracks suitable for the M88
To be honest I know very little stuff about M88 so I am not the best person to ask about m88 details.