-Must have alot of storage space

-followers can live there

-not riverhelm (bad voice acting)

Would you fancy "rolling your own"? Using the CK and a "build a dungeon" tutorial, you could knock up your own personalised storage area in under a couple of hours. You can then access this via the house(s) of your choice using a trapdoor/hatch - mine is just inside the front door of Breezehome, for instance.

Doing this will mean that you can add stuff to suit you, and make things more ambitious if you have the technical skills. I have a "stick your stuff in here" sorting chest which uses a simple script to relocate anything you put into it to one of a number of specialised chests (just an example). I didn't want to faff around with putting some items into Chest A, some into Chest B etc.