For example, this post from EquityMultiple is quite thorough (though you should always recognize the platforms will highlight the positive things about their particularly fee structure while minimizing the downsides).As @Mark Robertson pointed out, whether the site offers 506(b) or 506(c) investment can make a difference as well, and it's also important whether or not the site is registered broker-dealer or not (many, like Equity Multiple, are not broker-dealers themselves, but have contractual affiliate relationships with broker-dealers to offer the actual securities). 

The best paid tool  I use is propertyradar. ( I have no affiliation with propertyradar)

I was leaning towards a DC Keller Williams brokerage I know of due to the strong training and positive feedback I got from a friend affiliated with them, but would like other suggestions before I commit. 

(I am not affiliated with them, except as a property owner.).

(Full Disclosure - I am not affiliated with Wells Fargo in any way or benefit in any way).

They have an affiliation with coldwell, and my experience with them was not the best.

Please note I am not affiliated in any way with any of the groups other than that I have attended some of their meetings/presentations.NTAREI- https://ntarei.com/ Normally meets about 2x a month in North Dallas at the Holiday Inn at Preston and LBJ NE corner.

Human nature, regardless of party affiliation, eventually prevails.

.- Activities that count towards real estate professional status include those activities affiliated with a real property trade or business in which you materially participate.

I do as Bryan A. said - use same brand and just change outside parts that have key slots; tenants comprehend that the old key no longer has any chance of opening locks that are physically changed this way.I have seen the landlordlocks.com product demo'd in person, and that is the way to go once you get lots of units - mainly because you still can have a master key that accesses any lock.