My personal preference is a 300 series size wire crate… I use General Cage brand that fold flat when not in use or traveling. The size I use is 21 3/4 W x 30 L x 24 H
I have used these at home for all my B's over the years.. I also have that size in the RV for travel... However in my Van I use the small 200 size... which is fine for short trips... or shows... easier to lug around at shows...