Solo 401k custodian for loans

[Rikako W.]

I want to rollover my IRA into a solo 401k (I'm self employed) and borrow against the 401k for real estate ventures. Currently I use Vanguard which has the lowest fees, but they don't allow 401k loans. Fidelty doesn't allow loans either. What other solo 401k custodians are there that allow loans and have the lowest fees (and preferably offer Vanguard funds)?

[Jeff Nash]

None of the large mainstream custodians will include a loan option and they do not allow for true self-direction in regards to the way it is understood in BP (i.e.- invest in real estate and other alternatives).  The have very basic solo 401K options with more limited features that are not customizable.  That might work just fine for many people that just want to stick with traditional investment options and have a simple plan design. @Brett Synicky makes some good points.