You don't need equity. Profit margins are high. Depending on your particular expertise your services will be in demand for years to come (anything software-related). If you do it right you can work for several clients at the same time. At least you can always have a full sales pipeline so losing a contract won't be an end-of-the-world event for you.
Growing a consulting business beyond yourself, not selling your time but results, those are more of a problem but risk? Not really. At least not when compared to other businesses.