When Waller came on board initially as chief financial officer, the company was a marginally profitable sharemarket minnow, turning over about $8 million.
Ebos was also a far cry from the large, automated, slick operations such as Just Jeans Waller had worked for in the previous six years while based in Melbourne.
"I suppose as a young guy, I totally didn't expect the opportunity at that age and said 'get in there, give it your best shot and see what you can do'." The next few years were some of the toughest in his career.
In the early 1990s, major shareholder Brierley Investments sold out and in the break-up of the business the dental division was sold.
Its bread and butter business - local distribution for international brands - was being undermined by the end of the import licence era, says Waller. At that stage, Ebos was on very delicate ground, he says.
"That was really, really hard. Saving the company; travelling the world with a very young family; three weeks away at a time, just constantly, to try and find new opportunities to save the day." Too small to be a listed business, Ebos had to get to scale quickly and that meant acquisitions, says Waller.
The focus was on creating a business that followed customers over their lifetime, supplying pharmacies, primary care providers and hospitals.
There have been 19 successful acquisitions in the past decade alone, the most significant being last year's $1.1 billion purchase of Symbion, a leading Australian pharmaceutical wholesaler and distributor.
It's made Waller something of an M&A expert, and he'll stay at Ebos for another 12 months in a role focused on acquisition projects.
He won't divulge the secrets of his deal analysis but he does say discipline is key, including being prepared to walk away from months of work if a deal isn't right.
His rule is never to factor in synergy gains if that means firing people to make the deal worthwhile.
"Never do that; never pay for that.
"If that comes about as part of a logical efficiency move or a market dynamic that's different, but we never, ever push that and we have a rule of whenever we do a deal to try and buy really good companies with good people."
Until the Symbion deal, the head office in Christchurch had only five staff.
"We don't have spare people to put into companies if they go wrong. That in itself means there is not corporate arrogance so we've got to make sure we buy good businesses, don't hurt them when we buy them and really motivate the people in them to perform."
Waller's own pay, which topped $3.5 million in the last financial year, has made headlines in his hometown but he says it wouldn't have raised eyebrows among Ebos staff who know it is the result of long-term incentives.
A focus on rewarding performance was introduced by shareholder and director Peter Kraus in the early '90s because he didn't like the way New Zealand businesses gave staff a base salary for turning up and a little bonus at the end of the year "if you are a good boy", says Waller.
Ebos itself now has an annual turnover around the $6 billion mark, with a good chunk coming from its Australian businesses.
The company, dual-listed on the ASX, has owned businesses in Australia since the mid-1990s and Waller relishes the business environment across the Tasman.
He says Australian business people work extremely hard and are prepared to take more risk than their New Zealand counterparts. "You've got to capture that. It's actually a big plus if you can channel it right."
Today will be the first Ebos annual meeting in 27 years where Waller will not front to investors as the managing director.
Australian-based Patrick Davies, who previously headed Symbion, took over as chief executive last month.
Successful big dollar deals in recent years have created a situation for Waller he says was every bit as challenging as his early days at Ebos.
It involved some soul-searching about his role at the company and whether he had the passion and motivation to continue making the bold business moves required to take the company into the next realm.
And he'd always imposed a deadline to be out of the job by the time he hit 62.
That cut-off date ticks over late next year at which point Waller will become Ebos' independent chairman.