It doesn't matter how your motor/trans sit as long as you have clearance and the driveline is phased ( in correct angle ) .
I don't think GM performance oil pan will work . Fbody is the only one has enough ground clearance . A modified C6 oil pan might work too if your motor sits high enough . If you modify Fbody as I suggested ( not like mine ) , you will able to fill it to full capacity . Dipstick will indicate a little higher , just make a new " full " mark , oil will not interference with crankshaft .
As for the wiring harness , you will need everything minus emissions . NO : rear O2s ( post cats ) , EVAP , secondary air injection ( if equipped ) , EGR ( if equipped ) . Make sure VAT is removed from PCM and all related emissions are deleted .
Good luck .