When I owned a business, I offered a simple IRA through Vanguard.
There were no fees for the simple IRA. If I had chosen to offer a 401 through Vanguard, there would have been fees.
Both the simple and the 401 plans could invest in any of the Vanguard funds.
What type of business do you own? How many employees?
I suggest you also check with Fidelity.
I do not think we had to file any documents associated with the simple IRA program.
You may find that the big administrators are cheaper and more flexible than the small administrators.
Good luck! --70.188.xx.xx