If you don't have the time get with a broker in your area that specializes in investment property. An investment broker will have ties to many investors who purchase in bulk and then wholesale off to retail investors.
Work your numbers and explain this is the return you want to the broker. Explain if they can't find that return you don't want to look at the property. Remember there is much junk out there. You have to find the diamonds and get to them before someone else. Estate sales are great as they need quick cash because of the taxes of managing an estate. Usually the properties have a lot of equity but need repairs and updating.
A regular seller with 70k of equity will most likely just sit on the property and not sell. You would need to CREATE the equity in the form of a commercial short sale or repairs needed to the property increase it's after repair value. Also if you buy a duplex that is rented out for say 700 a piece but it is rundown and rents in the area are for 900 average a month then you know what to do. You buy it and then fix up the place and the up the rents to 850 a month and clear 300 more a month.
Remember full occupancy is not always a good thing if the property has deferred maintenance,questionable tenants,and rents are to low.
It sounds like you really need to use a broker as you do not have time for the upfront legwork which is fine. Many passive investors out there like doctors,lawyers,investor groups,etc.