As every bass is different, it's hard to know how a string will work until you try it. I've never played Helicores so can't comment on those. I had Evah weichs and found them higher in tension than Spiro weichs on my bass. Innovation Honeys were a good choice. I've had both Velvet Blues and Animas on the same bass and whilst the tension was very similar, the I much preferred the Animas, but they are pricey.
Trying to find low tension and high volume might prove tricky.
Good luck with the search.