Michael, you can propose a payment plan for the company and then one for the individual with the step up when the alimony ends. The one-year rule only applies to individuals, not businesses, but you could use it for the individual here if you wanted to.
If you set up the payment plan for the company and for the individual now with the alimony factored in, will it full-pay? If so I might go for that and that way the client gets breathing room when the alimony ends. If it wont and the IRS is balking then I would suggest the step-up after the alimony ends.