I'm with the Sheriff on this one: You've got a few different options worth exploring, but it will really depend on your bass and what you are going for.
I agree with Spiros on a darker bass. They can be too bright on some instruments, especially the top two strings, but they work really well on the bottom of a lot of basses, both arco and pizz. There are a lot of different flavours out there though, so depending on the tension you and your bass like, you might have to experiment a bit to find what you are after. Spiros also take a while to break in and get to where everyone loves them. Depending on how much you play this can be a couple of weeks or a couple of months. If you like that dead Spiro sound, you might be buying your first and last set of strings for the next decade or two.
Permanents to me are a more bow friendly Spirocore. They are still bright, focused, loud, have good sustain while being more forgiving under the bow, especially on top. While there definitely isn't anything wrong with their lower strings and I enjoyed them when I was in 4ths, they also pair really well with Spirocores on the bottom.
Evah's are a different direction for crossover playing. They tend to be darker and have more pizz "thump" to them. The Weichs are fairly popular as a lot of people found the Mittels to have way too much tension, although that works on some instruments and the weichs don't work on others. If you are looking for a darker arco sound and more old school pizz than spiros, Evah's might do it for you.
The Passione's really aren't a crossover string. They can be great for orchestral/arco work, but I have yet to meet a pizz or crossover player that has been happy with them for that side of things.
Belcantos are similar. They are a great orchestra string for a lot of people, dark, smooth, chocolatey etc. but they really lack sustain pizz. If you're looking for a "thump and die" kind of string pizz they might work, but I would look elsewhere first.
The D'Addario Helicores have been re-vamped since a lot of us hated them years ago. Other than a fair number of "you should really give them a chance again because they're a significant improvement from what they used to be" reviews here, I can't comment on them too much. They are a much more affordable option than some of the others though, and apparently the Hybrids are pretty good now.
I've got two Flex Deluxe strings that are going on top of two Spirocores that just arrived in the mail today. I'm excited to give them a try and from the reviews and conversations I've had here they sound like they should be a really great string for my mostly orchestral but occasionally pizz playing. I'm off to the Post Office to find out.