Whatever I recommend is gonna meet with some serious disagreement here...so I'll abstain.

NOT.

The RB-1, to me, is an "un-elegant" bike. That would be my commuter, even though it's got a fan following that will not agree. Just opining. Doesn't mean it's not a great one, but compared to the other two, it'd be my commuter.

The MXL is a good bike at almost everything it does. It's newer, and not the petite beauty that an '89 Paramount is. However, it's a great 60-miler bike, and I'd probably put your modern stuff on it and depend on it for your first century. If I've heard anything about the EM's, it's that they are utterly reliable.

The Paramount would be my delicacy, and I believe 8-sp DA is a great fit. norskagent here has an '89 with 8-sp DA STI and it's a gorgeous, classy ride.

That's my take.