He was born in Charleville to schoolteacher Laurence Edward Coomber and Sybil Harding, née Lightbody, a secretary.
After an unsuccessful run for the state seat of Currumbin as an independent in 1986, he was elected to the Queensland Legislative Assembly in 1989 as a Liberal.
In 1992 he challenged National Party leader Rob Borbidge in Surfers Paradise, but was defeated.
His association with Terry White strengthened, to include holding a position on the group's Board.
In 2018, Coomber's operating company entered administration and was eventually wound up by liquidators in 2019 with unsupported liabilities in the order of AU$19 million.