I can't recommend what you should do, but I'll tell you what I have setup to do. I also am a single employee business owner.
So end of last year I sat down with my accountant and we laid it all out, I had a traditional and Roth IRA at the time and setup a single 401k. We were too late last year to setup and fund the s401k and take the tax deduction so we did Roth and traditional for last year. I might skip the Roth some years when my income is higher than expected and try to look for as many tax deductions as possible. My account in 10 minutes or less can give me a couple of estimations with the tax deductible accounts vs not. I personally try to pay as little as legally possible in taxes, so Roth's don't always appeal to me, but I do have one setup and is funded and in down years I plan to max it out, because they are nice especially when I am 30 years away from retirement.