Even if you can defer them to closing, they will add to the amount of cash you need to bring to closing. 

There is a big learning curve to doing this wellThis type of deal is best done with someone with a decent amount of experience....it can be done, no doubt and be very successful.....but for a complete newbie?

For example, the skiptracing VA does get good phone numbers for a really cheap bulk amount FIRST (@Ryan Blake) and once I literally can not get in touch with the homeowner after having my caller VA's calling each number (30-40% of the leads unreachable) I would use a skiptracing service a pay about $1.35 for each lead ($40 monthly no-contract subscription).

@Wilson Bunton While I am not a licensed engineer or architect, I do a fair amount of work in AutoCAD and Revit to create sketches and construction mark-ups in my day job.

For such a small amount I would get a personal loan from somewhere for 20k and buy it cash.

In Portlandia were are see price concession and or free rent etc on some of the new build real high end 2500 dollar elevator buildings on the east side.. this is happening now.form what a friend of mine who owns a management company with 6k plus doors was telling me at lunch.a few buildings are stressed right now.take this scenario.. you buy the land 3 to 5 years ago it takes at LEAST 2 years to get through permitting then another year to build.. cost of building in this time has gone up 10% or more.. land is static .. and your proforma show this ever increasing rent.. you now come on market and your 4 story elevator building now cost you 400 a foot to build.so your in a new apartment 400k.. you need 2,500 a month just to hit your investor grade 4 to 5 cap.. and now rents start to pull back as they are or lease up is very slow at those values.. so you have full amount of debt on the building and of course everyone these days has max debt.. so debt service and DCR ratios start to go out of wac  you have annual reporting and loan covenants .. you no longer meet your covenants and you have a cash call to your lender  along with negative cash flow.. this is what I mean by some are stressed..

I'm not new to investing, but I am new to re-investing cashflow and I haven't found much if any info on what a "safe" amount of reserves would be. 

@Jay Hinrichs Unlimited amount can be raised. 35 sophisticated and unlimited accredited can participate in the 506B.

There was a good amount of rent that had not been transferred and also a large amount which the tenants never paid.

Of course it's going to depend on the deals you find, but if I were doing it, I would simply run the numbers on each deal, and whichever produces the highest amount of cash flow I'd go with.