i have a 22 inch round hoop that i got at an antique store. I do have to hang it on the back of a chair so that i can get my hand underneath it when i hand quilt. Then I decided to put out the money for a Harry Barnett 16 inch square hoop w/ a bean bag base. Harry's hoops are all individually hand made and they take about 8 weeks to get, but well worth it.
LOVE it!!! It does have a swivel base, and I really like that, too. No more hanging my hoop on the back of a chair.
http://www.laptophoops.com/