Yes, alternator is still available. I believe it's the 120 amp model because it has "120A" stamped on the case. The top mounting hole was bored out to 1/2" for an eyelet bolt to attach the engine torque strap .
Yes. The factory bolt will feel a little loose in the hole until it's tightened down, then it should be okay. Or just replace the top bolt with a 1/2" diameter bolt from the hardware store.