IMO, when it comes to fasteners, use the best quality you can... it's what holds the motor together, so I wouldn't skimp just for a few dollars saving. ARP is the way to go!
If you plan to run serious boost, you should look at flame ringing the heads/cylinders. They call it "Nerosisting" I believe. It'll handle boost presssures in excess of 1.4bar and you won't have any leakage issues. Worth it for the extra peace of mind.
Most big power builds opt for the GT2-EVO cams. Any reason why you chose 964 CAMs?
'89 911 Turbo Cab
Protomotive MAP ECU, Twin Plugged Heads, GT2-EVO CAMs, 3.3L fully finned P&C's, ARP fasteners, C2T head gaskets, Titanium Retainers, Turbo spec valves, springs & guides, 964 splash valves, GT35R BB turbo, GSF Stainless Headers, Magnaflow Exhaust, Full bay Intercooler, TiAL 46mm w/gate, TiAL 50mm BOV, Apexi AVC-R EBC, SPEC Stage3+ Clutch kit, Crane CDI Ignition