I am 30 years old and since i graduated college at 22, I have always attempted to max my 401k and roth ira.  

For all cash buyers, find title search with words of custodians of RE IRAs. 

I read some of the posts about self directed IRAs but still feel a bit unsure.  

We filled out a similar application to a mortgage; they did an appraisal of the property (included in the app fee of $100), ran our credit, wanted to see the signed leases for the other properties we had, bank statements, tax returns, pay stubs, all 401K/IRA statements, proof of funds, etc.

The fact that you can still use those funds to buy investment property using tax-deferred environment makes the first option even less appealing.I would suggest you you explore the option of using truly self-directed Solo 401k instead of SD IRA.

We are about to inherit our seed money for our flipping business, it is coming from a 403b account, misc IRAs (which are becoming inheritance IRAs), and sale of a single family property.  

I want to have my girlfriend change her Roth IRA to a self-directed Roth IRA.

Private Lending  Loan to LLC or entity, backed by the property<3 year term7-12%70% loan to value for a new investor/clientFund in 2-4 daysSelf Directed IRAs (Mountain West IRA) Works for any investment properties Works with partnerships (you can partner with your IRA)$200 -$1,850/yearEasier when a loan is not involvedLoans would need to be non-recourse (not secured by collateral/the property), which means a higher rates* The scenarios above were specific to the individual presenters, each of whom serves as a local resource whom we deem competitive.

I'd also figure in those expenses each month in the rent.. since Id already have a $10k safety net that additional rent collected to cover damages and vacancies would just go into a Roth IRA each month (Can always pull the principle out if needed). 

Most of the time, these folks will roll the lump sum over to an IRA.