Fullcount, Of the two bikes you have, the Jamis would be my preference as long as it fits. Have a bike shop perform an overhaul if you presently lack the skills to insure reliability.
I'm not a real fan of trailers, but they really do have their place and the Maya seems an appropriate, less expensive option than a new expedition level touring bike and you can pack your gear in a fashion you're accustomed to.
I used my hardtail mountain bike at first and it performed well. I built up an older tourer because I prefer drop bars on the road and use the mountain bike for what it does best.

The mountain bike will be used again for an offroad tour my sister and I are planning, however.
Brad