RE: name that boat? brushless jet boat candidate?
No, it's not too heavy at that size. You do not need to worry about weight as much as in the past. These days we have power for even the heaviest of slugs.
At this size you may want to go with a 6s setup.
I'm not a jet guy and wouldn't know if it would work well. I do know that submerged drive must go.
Ryan