Hi, I recently set up a sole proprietorship & transferred a Rollover IRA into a Solo 401k.

While 401k plans can allow for what are referred to as "in-service distributions" to rollover to another plan, most do not.  

If you qualify, you could roll over your 401k to a self directed IRA and invest in real estate WITHIN your retirement plan rather than raiding it.It's the best of both worlds.

What do you think about doing a rollover to an ira and strategically transitioning it to a Roth IRA to JV?

I feel like for what I am buying for SFH is more what I need to be looking at but I would like to get a MFH for LTR, if possible to maximize my cashout refinance to roll over into other properties.

What are the defining factors that I should be considering when transferring 401k rollover funds to 1 of the companies.The questions I have are;Cost of setupAnnual FeesFees per transaction Any other fees which I should be considering?

More than likely you will have left over tax money to roll over onto other properties that you are invested in. 

@Chad AckermanIf you are self-employed with no full-time employees and have funds in a former employer plan and/or non-Roth IRA, you can set up a Solo 401k, rollover the funds and then take a 401k participant loan.

Also the balloon rollover was great advice. 

The legal logistics to make that work assuming some investors would want to roll over and others would want to be cashed out, is not something we've tackled yet.