I'm not a tax professional, but I do my own taxes on my own business. Here are a few things to consider:
If you set up a 401(k), you still have to pay payroll taxes (the same as self-employment tax on schedule C); half from the business, half from you. On a Traditional IRA or 401(k), you will pay taxes when you withdraw funds (and a penalty if you withdraw those funds before age 55). With an IRA, you can also opt for an employer match, though I can't remember what tax liability that match incurs.
Another option is incorporation, or having an LLC be taxed as an S-corp. This way, you can pay yourself a fair salary, on which you will pay both payroll tax and income tax; but then you don' t have to pay income tax on the profit.