2 Questions?

It has been pointed out to me by some posters here, that generally higher-end speakers are not so forgiving with poorly recorded music much of what seems to be 70 - 80's era rock.

Room treatments aside (and without cutting holes in my walls to vent my speakers outside as some have suggested).
I am looking for some advice from others about what speakers have worked well with this situation?

Currently running  Roon Nucleus through a W4S 2v2SE Dac tethered to CODA CSiB V1 configuration  
(150 w @ 8 ohm) integrated amp.  $3,000 ceiling, give or take.

Second question: Is there a decent quality speaker switch that I could hook up to my amp to simply toggle between two sets of speakers? My amp has 2 speaker outputs on the back but no A/B switch to change from one set of speakers to the other.

I see there inexpensive switches offered that have limited power ratings (eg: 100 watts per channel). Are these sufficient for doing the job? Will these switches have a negative effect on sound quality? Thanks.