5 string tunings and string gauges

I recently purchased a 5 string bass with the idea of tuning the top four strings up one whole step to go with a guitar in drop B tuning. I've been told this would require extremely light strings to loosen tension, or the neck will be destroyed. Any advice on what string gauges would work well for this?
 
I recently purchased a 5 string bass with the idea of tuning the top four strings up one whole step to go with a guitar in drop B tuning. I've been told this would require extremely light strings to loosen tension, or the neck will be destroyed. Any advice on what string gauges would work well for this?

Your best bet would be to ask Michael Manring on his forum. He's the string and tuning expert!!! Have fun!!!
 
D'Addario also has a string tension/tuning matrix pdf that you can download to find the proper strings for the same tension as conventional tuning at the pitches you're wanting to play as open strings. I have used their chart for years for exactly such applications, including alternate bass string tunings, guitar open tunings, "terz" tunings, etc.