One possibility that comes to mind was an early ARF of similar configuration and size was the Lanier Sea Bird , although I cannot remember if it was a T tail or not. It was of the typical Lanier construction with plastic molded around a plywood structure. Having seems in the hull it leaked like a sieve.
I tested one many years ago for a fellow down at lake Havasu and was not impressed. Whatever your airplane is I suspect you will have to fabricate your own nacelle. If you do I would suggest you build in around eight to ten degrees upthrust in the pylon. This to avoid many of the problems some hi line podded seaplanes can encounter.
John