I need small advise for string gauge for guitar and bass. My band plays in B standard now, however we want to tune whole step down to A standard. I've got now in B standard 7 string with 62-13+10 (25.5) scale and bassist has 4 string bass with 135. strings (34 scale)

What gauge we need to tune whole step down? Can't find really good answers around, so sorry for thread and also can't find any tool for this. lookign for some 17.0 pounds tension or higehr and bass for some 35-40 pounds.