Double Bass Strings

After doing three jazz and blues gigs over the weekend on upright bass, my plucking-hand fingers "sting" - no blisters, thankfully.

I am looking for double bass strings that are soft, have decent volume, and stay in tune in extreme weather conditions. Any suggestions? I have tried many strings in the past, but it is getting difficult - and costly - to keep up with all innovations.

Any help will be much appreciated.