Rb30/26 Harmonic Balancer And Run In Oil Questions

[stomper]

So, i have dropped in my short motor to start the clean and machining process. At the moment she looks like:

Rb30 block stock as a rock

CP RB26 9.0:1 Forged Pistons

Spool Forged Con Rods

ACL Main and Rod Race Bearings for RB30 (which may change to RB26, as we are deciding whether to water groove the mains)

GTR oil pump

GTR water pump

Tomei Metal gaskets all round including 1.5mm head

new splitfire CP's

RB26 OEM gasket kit for the rest of the replaceable gaskets

GT3540 with 1.06 exhaust housing

Link G4 ECU with 7 Bar MAP sensor

NEW ECU Loom.

R34 GTR Vspec Head

SARD 800cc injectors

Standard GTR TB and Intake plenum.

The motor is replacing an RB25DET making 235Kw ATW in a R33 GTST.

The questions I have are:

What Harmonic balancer do I use RB30 or RB26. I intend to use the RB25 PS pump, alternator etc from the current engine.

Also does anyone know the Gates part number I need to use for the timing belt?

Any recommendations on oil brand and grade for running in?