I also suggest Newtone Strings, i know they have made some extreme length/gauge strings for ERBs.
I've been looking for a manufacturer that produces low tension super long scale strings
'Low tension' is not a string brand characteristic, tension depends on what gauge and what pitch. Maybe you mean 'low stiffness'? in which case Kalium strings are indeed very flexible.
I don't really want to deal with Kalium because their website is confusing, they don't offer the guage strings I need
I cannot imagine how you consider they do not have the gauges you need, they have more gauge choice than anyone, .008 to .266 with gauge step size smoothly decreasing for thinner strings so that the tension steps between adjacent gauges are never extreme.
The conventional .005 gauge step is ok at .100 but impractucally huge at .040 or .025.
Likewise, a .005 gauge step is unnecessarily small for very large gauges like .150+.
Kalium gauge steps are smoothly varied to always be equal to the tension change of a 1 semitone retuning, this is the logical way to step gauges and only Kalium do this.
If you mean something like: you want a .145 and they only do .142 and .150, the difference is not large enough at that gauge to be a problem, just use the .142.
For most typical bass guitar gauges Kalium steps are smaller than other brands, so you actually have a finer choice of gauge, so it is actually other brands that do not have the gauges you need.
Very interested in seeing your instrument.