Better to just try some for a while and hear what it does. I've been putting together "balanced tension" sets from separates for a couple years now based on figures from D'Addario (seems to work with any strings of like construction) and went from heavey to way way light over time to feel and hear what the differences were.
Here's a good start for lighter nickel roundwounds:
Code:
gauge | tension in pounds
===========================
.040 33.7
.055 35.3
.070 33.7
.095 34.4
.130 tapered 34.5
Just for comparison, here's a balanced tension nickel set in .045:
Code:
gauge | tension in pounds
===========================
.045 42.8
.060 42.9
.080 42.0
.105 40.3
.145 tapered 41.5
I've found that balancing the tension seems to help necks too, and I love having a more consistent feel from string to string and not always getting the impression that the low E and low B (and G) don't quite match the rest of the set in terms of dynamics/punch. Standard sets often vary 10 or 12 pounds, these only a few.
The reason I specify tapered B strings is because when you get that much diameter the flexibility is less and it makes them tonally duller than the rest, but you can regain some with a moderate taper core.