@Keagan W PooleI'd recommend looking up Michael Blank and reading everything he has written on multi-family.

With all that being said I can offer you is (blank).The biggest piece of advice I can give you is this: Once you give that number don't say another word, keep your mouth shut and wait for a response...Then you know where to go from there.  

Many rental units have been added in the Los angles for example and landlords are now staring to work with renters.

Yes, call a lawyer and have them do a quick form for you that you can use forever hereafter by filling in blanks (unless the circumstances are unique or change).

All that is fine, I'm just looking to fill in the blanks from there on - which lenders to look at, likely interest rates (ball park) and if they'd touch me at all.I have about $450,000 cash for the sake of this exercise, so I was thinking 40% lend could have me looking at assets up to $750,000.

Ready Joe Fairless and Michael Blank latest books will put you ahead of the curve. 

Yeah, I would literally google "Real Estate Wholesalers in BLANK" and a list should pop up.

During setup it asked to specify a DBA name or leave it blank.

I have actually attended both landlord training seminars, I did think that the City one was valuable (they give you an entire set of Wisconsin Legal Blank landlord papers) but it did not go nearly as in depth as Tristan Petit's course.

My suggestion would be to call (or your buyer agent call) the listing agent and ask him point blank what issues the house has that it hasn't sold for so long in a hot market.