SD401K vs SD IRA and Checkbook Control

[Marsha Segree]

I have been reading through the posts about self directed IRA/401Ks/checkbook control etc and there is so much information! I left my job a few months ago and I want to transfer the funds from my 401K to one of these types of accounts so that I can use the funds for investing in real estate. I have an LLC so one of my question is, would it be better to open a solo 401K or open a self directed IRA? Fidelity offers solo 401Ks but I came across the website for Accuplan. Does anyone have experience with Fidelity and/or Accuplan? What questions should I be asking when I contact these companies? Thank you.