Alot. There are many thousands of different pieces of physicial therapy equipment needed depending on the condition being treated. There are many different companies that specialize in this type of equipment. Try your favorite search engine for an online search of providers of these devices.
Depends. Equipment can range from simple theraband to elaborate traction equipment.
No equipment. The best physical therapy involves posture and activity reeducation, stretching, strengthening and working on the floor, with mars balls and rubberbands. You don't need any fancy equipment, just a good therapist.
Treadmill And rowing. Treadmill and rowing machine could provide a good start for home physical therapy.