I have an '84 610 as well. It's a great bike and will make a fine touring bike.
Have you used moustache bars? In my opinion, they look good and perform terribly. There really aren't that many usable hand positions and none of them worked for me. I'm pretty easy going when it comes to bars and these are the only bars I've actively disliked. Your mileage may vary obviously.
If I were going to run flat bars on a road bike, I'd take a long hard look at trekking bars. I use them on one of my mountain bikes--a '92 Trek 950--and they're great. They have lots of usable hand positions. Just think of them as a drop bar squished flat.
1984 Trek 610
1992 Trek 950