While it is admirable of Tracy to offer his firms 3(38) services that is merely a piece to the puzzle. There are many parts to running a fully compliant plan and I would argue the investments are the easiest piece to control. Administration & Compliance are the far bigger concerns that is why you need a true Open Arch PARTNER not provider to help control costs and get the hands on service the RPF needs to run the plan not an 800#. Alliance Pension Consultants, Epic Advisors, CDM, BCG Consultants are some terrific options. Also look for a 402a Independent Named Fiduciary to oversee the whole plan for you to fully ensure compliance.
For small plans (<$10mil in assets) I've found John Hancock's 401(k) offers a robust, competitively priced platform. They also recently moved to a more transparent fee structure recently (http://www.thinkadvisor.com/2014/03/06/john-hancock-changes-401k-plan-pricing) that eliminates a lot of the conflicts in how participants pay plan expenses. I use this platform for all of my small 401(k) plan clients.
Fidelity, Schwab, Vanguard, Principal, Transamerica, and almost retail mutual fund company. Fidelity, Schwab and Vanguard are probably the best.
If you are looking for ease of use and low fee structure I would look at ANICO's. They have over 35 choices and a nice flat fee structure. If you are looking for investment choices, flexibility, and access to active management in your plan Flexible Plan out of Michigan is an excellent choice. They provide great diversification and a personalized plan for each person on your team. As a platform it can depend on the size, but Fidelity typically runs the lowest as far as fee structure whether you use a per trade cost or an advisory fee. As you can see, the best thing is to shop the market a bit before diving in.
To add to the previous posts... as someone who reviews plans of all sizes and forms I can honestly tell you there is minimal difference in fund choices among them. I utilize the pain points my clients have had in the past as a recipe for providing a truly great plan. Do your work in finding an advisor that clearly shows you a "Commitment to Plan Services" so you know exactly what they are offering in the servicing aspect, which is #1 in complaints I've seen from folks looking to move. Next, think about your employees... form a plan that fits their style the best. Are they internet savvy? Will they be active in the plan or put money in and never look at it? Do they need/want onsite education on an ongoing basis? Find someone who is organized, a company who has a proven track record, and someone you feel can provide a better service than you are expecting.
I hope this helps!
Vanguard has recently started offering a great "starting" 401(k) with Acensus. The great thing that is unique, beyond the usual very low costs associated with Vanguard, is that you will work with an advisor that takes on the fiduciary role for you. This is VERY unique and is an extra layer of protection in the 401(k) market. I would recommend looking into them and to find an advisor that is able to work with them for you.