Jimmy,
To start, the lower the amount of money you put down the lower the risk because if you loose the property for some reason you haven' t lost any of your money.
Getting in is difficult with no money down, though BP will make it sound quit easy. I think this is relative. For someone who knows the area and can do their own searching buying w/ no money down can be simple...still difficult, but simple.
My suggestion would be to start small if you are going to invest here in SD. I'd start with a 2 unit and get to know the ropes. With your schedule it will be a balancing act. Jumping in too deep with 8 units might be too much and will cost you more in the end.
I had these three clients who were all in the military and were all friends. They bought a 4 unit together. One lived in it and the other two rented a place together elsewhere in SD. They worked on fixing it up over time. A little over a year later they called me saying they were ready to buy another property. So we found a 2 unit. The two that were renting else elsewhere moved into one of the units, rented out the other and then started working on fixing it up. They are currenlty exploring the option of buying another one, but I suggested we wait because one of them might be getting stationed on the east coast.
I hope this helps. Maybe this will spark an idea for you!
Karl