You can pay for varying depths of analysis, but I'd advise caution on what you think the data might tell you. To know if / how he's related to people in the last century or so, you'd need samples from them to compare. The ancestry patterns that can be determined from your husband's DNA alone will indicate a broad sweep of homelands that his paternal ancestors passed through. Some tests offer to identify the most ancient known female ancestor, sometimes called 'Eve clans'. You might even be able to get the extent of Neanderthal DNA included in the test. But they won't throw light on his recent familial connections.
Unless perhaps it's staringly obvious, eg his DNA indicates his close ancestors are all from subsaharan Africa whereas he's been given to believe they were from Dublin.