I also doubt very seriously that any brokerage/custodian is going to allow this kind of loan with 401k assets; it's likely going to need to be a 401k general purpose loan, which is highly regulated (as someone else mentioned). 

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

Its proximity to campus, turnkey condition, and rental history make it particularly appealing to investors seeking high cash flow and low vacancy risks.

The idea is to convert a multi-family building into condos; but not in the traditional sense where you separate pre-existing apartments into their own condos; but in a way where you combine the common areas of all of the apartments in that whole building, and turn the individual rooms within those apartments into condos themselves; thus transforming the hallways, kitchens, bathrooms, living rooms, dining rooms, porches, balconies into common areas of the condos. 

Hey Account Closed - I highly suggest  using a renovation loan and house hacking a multi-family if that is possible with your current life circumstances.The 203k and homestyle renovation loans are just amazing products and drastically help you reduce your risk, in my opinion, because you are able to leverage the cost of the entire renovation with such a low down payment loan.We work with a lot of clients who use these products in Chicago, and no matter what, in the long term, they gain great equity.If you aren't able to house hack - the process is essentially the same, but just with more money down with hard money or conventional construction loan.

Well the family members trashed the apartment and left me to clean it up and rehab it.

very high risk even I only do them with very specific investors in mind and a plan. we dont flip land we develop every one. 

I have done this before and now find the risk just to high.  

IT's the worst place in the world to be a landlord and very high risk.

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.