I don't know the rim well enough (at all) to render a guess about the max tension it can take. I usually determine that by looking at the thickness at the spoke hole, and by gauging the rim's radial rigidity. But as I mentioned earlier I'm not a big user of plain spokes, and if I were building your wheels I'd probably use single butted 13/14 spokes for the right rear and 14/15g butted spokes for the left (possibly even 2.0/1.7/2.0). Going with the butted spoke on the left side frees me somewhat from the minimum tension requirements, and allows me to build a decent wheels with tensions someplace near 60kgf left and 100-110kgf right. (depends on the dish)

Odds are those rims can handle tensions in the 120kgf range maybe a bit higher (watch as you build) so you can set he right tension higher, and have upside room on the left (handy with 2.0 plain spokes).

BTW- I don't set tensions based on a predetermined number. I build and tension to a working point, then flex the rim and observe tension drops. Watching how tension changes under load and deflection tells me where I need to go, and that's also why I don't depend on a tension meter.

Using a tension meter depends on knowing in advance what the target is, and is fast and convenient if I'm building wheels with stuff I've used before. However with unfamiliar stuff, I have no way to set a target to measure against except for a wide band, so I let the wheel tell me if it's OK or not.