AC4100

I have one of these in each of my bedrooms. They are inexpensive, though kind of loud. They work great as a sound machine at night. Honestly, I'm not entirely sure of their overall effectiveness...or that of any air purifier. Sometimes I think they're just a sales pitch for money. I notice a much bigger difference in dust and odors when I stay on top of vacuuming and other cleaning. Since they have a physical on/off switch, I connected each to a Zigbee plug and integrated into Home Assistant. GermGuardian Air Purifier for Home with HEPA Filter, Removes 99.97% of Pollutants, Covers up to 375 Sq. Foot Room in 1 Hr, UV-C Light Helps Reduce Germs, Zero Ozone Verified, 11", Silver, AC4100CA https://a.co/d/gnGXI0n

Get a HEPA filter. You can actually get one for your central air system if you have one. But you can also find them very inexpensively  I got this one years ago https://a.co/d/0Zs3TI8 and have been pretty happy with it. I got it for dealing with wildfire smoke. Pretty much anything is good as long as it's HEPA. You can also get pretty far with DIY solutions that consist of sticking a fan onto a HEPA filter. 

I have a GermGuardian setup to blow right after my boxes. It’s the ~tabletop-sized one (that requires E filters). I have it on top of a low-height wooden box for shoe storage. So it’s ~18-28” above the ground. That seems to do wonders I also have a PetFusion privacy gate that blocks the area around cat boxes. It’s made of wood frames and semi-opaque plastic in the middle of the 3 panels. It’s maybe 3-4’ high. I think it does a good job of keeping in the litter and the smells The air purifier blows over cat boxes and is kind of corralled in the litter area, thanks to the walls and this cat privacy screen

Blues air or GermGuardian with UV. I’ve had mine for years and it’s been great

For less than that I got two germ guardian hepa air filters, and a Bissell hepa vacuum.