Thanks. Assuming you will tune to Bb standard:
Physics would suggest a .135 or .140 to maintain the same tension at Bb. The Kalium tension chart, based on actual string mass data, and using it to approximate other brands, suggests the same. Maybe try a .135 first as they're much more available.
The sequence .105 .085 .065 .045 has the middle 2 strings tighter than the others. So i suggest using a .110 to maintain tension on the Eb, but leave the .085, .065 and .045 the same, since you find the D tight (indeed in most mainstream bass sets the D is tightest).
Why not use a .050? Because going from .045 -> .050 is a huge increase in tension, even though you are detuning by 1 semitone the tension will still rise significantly.
So .135 .110 .085 .065 .045.
Unfortunately most string manufacturers use a gauge step of .005 across their range of gauges, but .005 in .045 is almost 3 times as much change as .005 in .130.
Kalium, for example, smoothly adjusts the size of the gauge step across their range of gauges, in a way that keeps the tension change caused by a step equal.