You are a bit between things with these instruments. We've built them for quite some time, and a lot depends on how they're built.
A longer scale needs a little more tension, but not much more. Most Concerts are built pretty light, and if you follow that road, you don't need the tension you do on a bigger Tenor soundboard.
We use our Soft Lights - they have a bit more volume than standard Lights. Mediums would work too - they're more typical of Tenor gauges, but we just feel our instruments respond better with less tension.