This is the exact basket I'm using now:

https://www.amazon.com/dp/B0922Z67KK?psc=1&ref=ppx_yo2ov_dt_b_product_details

A gazillion 54mm bottomless portafilters available via Amazon and otherwise. E.g.: 54mm bottomless portafilters -- Amazon.com

Likewise, baskets. E.g.: 54mm baskets -- Amazon.com

You especially may be interested in the IMS Precision 18-22g basket (other sizes available as well): IMS Precision 18-22g basket (plus other sizes) -- Amazon.com