Wattage isn’t really a good measure of sound quality.  I’m not saying those amp options are bad, but I definitely wouldn’t assume they are equivalent to Sonos ZPs just because they have similar wattage stats.

Are there speakers already in the basement?  It’s kind of implied by your statements, but couldn’t tell for sure.  I wasn’t sure why you were looking for an amp rather than other options.  Also, where would the amp be located relative your basement?  Bluetooth has a limited range, so if the distance is through a couple walls, a bluetooth amp may not work that well.

But anyway, my personal opinion will definitely be subjective, but I don’t like to buy used equipment that is already out of date.  A Connect:amp is compatible with S2, so you aren’t locked into S1 there, but still not as good as a Sonos Amp and all the features you get there.  Even if you can’t use the features, you may have a need in the future, and you’ll get firmware updates you may be happy about later.  So I would go with the current Amp, or Sonos speakers if it were me.

However, I understand going with the cheaper amp option, especially since you haven’t lost much if it doesn’t work out as you hoped.  You may even be able to try it out and return to Amazon if it doesn’t work out.

Thanks. The house came with speakers already installed and 3 zoneplayer 120s so I am locked into S1 unless I upgrade everything.  The basement speaker wire connection is in the basement room so no issue with Bluetooth reception from gym to Bluetooth amp.