Hi everyone! I'm a bit new to the community and appreciate any help here. 

Quick background: my partner (50/50) and I have done three deals, all very positive land/flip experiences. I've owner financed sold two of my previous primary residences, so I have a very moderate amount of experience.

We are now looking to buy/hold/BRRR strategy in a newer area, and was just speaking with a local agent about a multifamily property I was interested in. Long story short, she asked how many we were looking to purchase long term. I shared with her that we are beginning slowly, but want to ramp up to quite a few in the near future.

She told me she has a very close friend who is retiring and looking to exit his real estate interests in the same area as I was looking. He currently has over 50 (not positive on the number yet) each with 2 or more doors (some duplexes, tri-plexes, and quad). Rents in the neighborhood range from $500-$700 per unit. She said he was looking to cash out at around $90k per unit (not per door, sorry if I'm not saying this correctly). I would think we could talk him down to $80k or $70k per unit. There is currently around an 80% occupancy rate that would not change. 

We have a team in place in the area (my sister is local and would manage the properties for the time being, as well as contractors etc that she has used and trusts). So, my big questions are:

1. How much cash would one need to pull off a deal like this (i.e. how much does a bank require in a down payment for such a transaction)? 

2. Would it be better to go through a local bank or a national bank? 

3. Does this sound like something that is viable and feasible? 

4. The units were all built in the late 1970's and early 1980's. Appraised at the county for around $45-60k per, however there are three for sale in the area retailing around $97k-$110k. 

Thank you for whatever wisdom and help you can provide, I sincerely appreciate it!