I think it is the B20 gasket that you use.
Timing belt depends on the water pump - for B20 water pump use b20 timing belt, for b16, gsr, itr, ctr, etc water pump use the appropriate belt for that water pump.
You need B16 or GSR head studs (believe B-Series VTEC studs are the same). You cannot use B20 studs and DO NOT re-use OEM bolts, just get new ARP's or something.