hey to send the tools and adapters is a nice gesture and (for sure) a good start .
(No I´m not Jenson B...)
the Porsche LMP2 powerplant crossed my mind ,but that is also prohibitive(at 322000$!!! ) and maybe to long + crankheight also not ideal..
the porsche Gearbox fitting to it is huge...and expensive at 200.000$!!!
Have you measured the input shaft height at the gearbox? this will tell you were you need to aim for crankshaft height...
I heard that Brawn had to design a stepgear set for the adoption of the Merc engine in 2009 ..so was the Honda or the Honda engine the one with the lower crankshaft height?