Dowling appears in a grey long coat with fur-look collar, while Willis sports a fur-look shrug over a lilac evening gown.
Celebrity Big Brother's new series begins in January 2013.
Katie Price is said to be mulling over whether to join the Channel 5 show, with friend and most recent X Factor eliminee Rylan Clark also apparently having been approached.
Dowling has named Clark and third-placed I'm a Celebrity star David Haye as contestants he would like to see on the upcoming series.
The Only Way Is Essex's Lauren Pope recently told Digital Spy that she would never agree to go on Celebrity Big Brother, as being filmed on the toilet would "creep [her] out".