Hi,
there's a TP conversion for the BE58 P done by Royal Turbine, the boys and girls converting the Malibu into the "Jetprop DLX" and the Duke to the "Royal Duke":
Cougar Baron
Financially, it doesn't make sense to me, the conversion lifts the plane into the C90 pricing ranges, but I guess the initial climb rate alone is worth all the money, it's between 3800 and 4600 ft/min - not really practicable on the most SIDs but a lot of fun on a VMC departure :-)
Kind regards,
Peter