De Souza will focus on developing relationships at client level and will aim to increase the amount clients spend on out-of-home media.
Prior to working at Starcom MediaVest Group as marketing and business development director, De Souza was director of client planning at JCDecaux. She will report to national sales director Ged Weston.
Vidal will be responsible for sales from the media agencies Mediaedge:cia and Maxus. Most recently, he was senior account manager at Avanti Screenmedia.
He has seven years' experience in outdoor and previously worked at out-of-home agency Posterscope and now-defunct outdoor media owner Streetbroadcast.