I would say,if you got some money for a converter,make an eductaed guess for a converter with the info you have gathered so far,,,sense your combo is completely different than anything out there. Nobody will know what your engine needs.
So if you purchase a converter & it does not work,most places give you a free tweak one time., correct?
If that still does not work,youll be a lot closer to what your needs are for your engine.
Hey it's only money,& looks like you spent a lot anyways.
Racing costs money,& only with some R&D w/different parts will get you what you are looking for.
It's all in the combination, like you said yours is completely different.
You will have to throw down the $$$$ & experiment, sorry to say something you allready know.
Two cents & no offense.