i would suggest repairing the crank/new bearings
new decent oil pump (jun, nitto, greddy, tomei etc etc)
valve guides
sump extension/baffle (greddy the best bang for buck)
full nissan gasket set
and new rings
if you have more money chuck in a set of decent pistons and either arp rod bolts or a set of spool rods
and if you want to spend even more it will snowball and you will be up for around $20k