Ha ... traffic jam of good advice.
Eliakim, design a custom set using a tension chart such as http://circlekstrings.com/CKSIMAGES/...nsionChart.pdf
then buy single strings in your brand of choice by rounding the gauge to the nearest .005. Use the chart to discover what tension you like then choose gauges that give you that tension on every string in drop B.
is an excellent place to build a custom set.
Alternatively Circle K Strings sell 'drop tune' sets here http://circlekstrings.com/store/stan...4-strings.html
that are purpose designed to have equal tension strings in a drop tuning.
You could also tune your 5 string to BF#BEA to retain the higher notes http://circlekstrings.com/store/stan...5-strings.html