I know you can essentially find most of the information on each site, but feel like each one lacks enough customizable features.For example, in researching nearby markets, it would be nice to do a search for example, multi-family properties, in this price range, X mile radius from a zip code, relatively safe neighborhood, with a school rating of 6/10 or above with a "market temp" of medium-hot.

Podio is a little old-school looking, but very customizable and works just fine once you get over the learning curve.

A customizable Domain with a HTML editable page would be awesome.

@Chris Dawg Grant Street software for lien auctions usually has a customizable interface so you can download all sorts of property data from past auctions.

Easy to use property advertising, customizable lease templates, customer service is fantastic, responsive and you get to talk to actual humans (super polite and well informed). 

Completely customize able, no limit on the number of contacts and the paid version has workflow automation. 

The script is featuring 100 % source code, technical support, domain license, multi-currency, multi-language support system and it can be customizable for rental sharing website like car rental, boat rental, yacht charter, vacation rental.

A customizable fund like the ones offered by Avestor overcomes many of these advantages and combines the best features of syndications and funds.

Fully customizable 5.  

If you have dozens of units and need something robust and customizable, you'll want to look at paid options like AppFolio or Rent Manager.