I'd dearly love to use Spiros on my Alcoa, but my hands already have RA setting in, I like the touch of thick low-tension strings, and I do play 3 hour gigs (in non-Covid19 times). Plus, I'm after a less metallic tone with my Alcoa, so for this DB any kind of metal core strings are not a good choice. That said, if I ever get a "standard" wooden double bass, Spiros will be my first choice in strings, even if my hands don't like them for longer sessions...
I had thought generally about getting a 2nd DB, a wooden one, early last year and was already thinking about Spiros, but tending to some of our friends in Covid19-related financial hardship and later, getting our house re-roofed seemed like a better idea. Maybe someday, but in the meantime I consider myself lucky to have my Alcoa.
To the OP regarding getting a Vic's Model B instead of a Model C, if slapping isn't a large part of your pizz playing I don't think you'll have a problem, but be aware that slapping is getting some popularity again with many genre other than rocka-psycho billy and you may wish you had fingerboard coverage eventually. My first Vic's Model C was actually modified by the previous owner to disable the fingerboard pickup and basically emulate a Model B, and it actually did pickup slap relatively well if I pumped it up a little. (I didn't discover that it had been modified until I got my K&K pre-amp and tried to get both pickups to work -- talk about good service, Vic replaced that older Model C for free even though I wasn't its original owner.)