The move is part of a bid by the south London company to become a leading player in the display graphics sector through organic growth and acquisition.
"Having Ben's expertise is a great opportunity to help us grow from a boutique to the next stage," said managing director Graham Clark.
"I'm used to building up businesses in the downturn," Moss explained. "I think it's the right time to build a business and it means we'll be ready for the cream of the Olympics. The millennium boosted our sector by 20%; the Olympics brings a far bigger opportunity."
Moss added that a turnover target of £30m in 2012 "wasn't outrageous".
He will take on the new role in April following an 18-month stint of gardening leave after his departure from St Ives, which bought Service Graphics in November 2006.
Moss joins eight former Service Graphics colleagues who have moved across from its Jupiter Display division to McKenzie Clark in the past year.
UPDATE: Moss takes stake in McKenzie Clark
Ben Moss, formerly Service Graphics sales director, has taken a stake in McKenzie Clark and joined the firm as commercial director.