You'll be able to work out what off the shelf D'Addario strings to use at that tuning with their very helpful http://stringtensionpro.com app. You'll be able to balance up the tension and tweak it to your preferred feel. This is of course working on the assumption you are on parallel frets, as you may come unstuck if you have a 37" scale length. Then, in that case, Si's suggestion to talk to Newtone is highly recommended. They actually made me a 145 gauge string for a 34" scale bass that maintained tension down to F# which was quite awesome. However, a string with more mass made for the tuning will sound better. I.e., I'm just using up the last of my 183's for my F#.