Unlimited. You get 5 TB when you sign up. When you need more, ask them. If you the sole user, they'll just add it to your account.

I just bought a GH4 on eBay for $750, and the 14-140mm Lumix lens for $250.
These days it's easy to think the older tech isn't as great as the latest and greatest. I don't think buying a whole new camera to record 10-bit is worth it.

I convert all my footage to Pro Res HQ with EditReady, and sync the drive I'm editing with onto DropBox. Once finished (and after a year), I'll delete the local version. I can bring back the media files quickly. I tried this technique with Google Drive and lost media (or it rendered the media unreadable); DropBox has been reliable. I also use the DropBox Pro subscription, with is around $750 a year (cheap against buying hard drives), secure, and accessible on any computer with their desktop app.

I use DropBox Pro Business. It's $750 a year for 5TB, and as a single user, they'll give you a TB at a time upon request. The upload rate is fast; I tried Amazon Cloud and it was dreadfully slow. I also tried Google, but some of the files were unreadable upon downloading (after syncing).

I edit on permanent machines for clients (that have studios) as well as on my own laptop (a MacBook Pro maxxed).
Setting up an edit station for clients is the best way to work for them on location, as you connect with them and they justify your value. A decent sized monitor and keyboard, allows your client is be present, setting realistic expectations as to how long things take, which equals more billable hours (as opposed to working from home).

The monitor travels in the box that it came in, and the laptop in a Pelican case or padded backpack. A Mac Mini is also another portable option. With USB3 or Thunderbolt, storage can also travel.

Raney, stop thinking about not buying the NX1. I'm currently looking at this camera; it seems to have amazing specs! 4K isn't going to be around forever, so why should your camera?
I've owned Reds, Canons and Panasonics, and I know everything comes down in price after every NAB-it doesn't make sense to spend an arm and a leg on tech specs anymore. I've only bought a camera new once, and sold it for peanuts because it wasn't sexy anymore. So no more new cameras.
So let's get logical: Samsung NX1 with 4K at $1000, internally from a 6.5K sensor? Hmmm....
I don't buy cameras every day, and most times I don't want the hassle of renting. I just want to shoot with a solid camera that creates filmic images like Canon, has the inputs, has timecode, and doesn't crop the image too much. I want a Canon C500 that goes in my backpack.
Which is why the NX1 at $1K looks damn appetizing. It's also the closest to the Canon look I've seen. Don't kid yourself, neither the GH4 or A7's look like Canon-they just check off boxes for editors. I've been looking at buying a used 1Dc, but at $3500, it seems overpriced for a discontinued camera.
And Samsung lenses? There are plenty of them out there, but no one needs more than 3 lenses. And you don't need to "invest" in lenses-buy one good Samsung zoom with OIS. Use an eBay adapter for everything else-there are plenty for the NX mount. My total investment will probably be around $1500 to $2000, which is a drop in the bucket compared to an A7 camera without anything. GH4 is cheap, but you need adapters to kill crop and it's not very filmic (to me).
So keep looking at the NX1, but don't spend too much on it-there's just going to be something better soon. Make sure it's nice and cheap so you can throw it away in 5 years.