Hi 8notes community

I'm having trouble deciding what instrument to learn and I could use some external input...
The ones I'm deciding between are Viola and Cello.

So my background is:

I'm a 17 year old student that is currently a 7th grade pianist (tested by AMEB -Australian Musical Examinations Board) and am looking for a new instrument.

I thought about stringed instruments because I believe they have the capacity to input 'feeling' into the music they create better than some others, although I am aware that you can probably do it with all. I guess I just like the 'closeness' that you have to the sound with a stringed instrument. Please correct me if I'm wrong.

Anyway, money isn't a huge issue, as I have enough money for a decent cello myself (and therefore obviously a viola as well) and my parents will pay half/most for weekly lessons.
Having said that, part of the reason I'm asking this question is if prefer not to waste money on what might obviously be the wrong instrument for me through renting for a couple months (and then buying If I like it, it's something like $50AU per month to rent a cello.)

So, I was leaning towards Viola (I have a friend who plays it 6th grade) but then I heard of the '2Cellos' duo and practically impulse-bought a cello then and there.

Now I'm well aware that those two (if you've seen them you know what I mean, if not, YouTube '2Cellos thunderstruck' ) are music wizards that have come from a music family background and have studied the instrument hard for many many years. However it kind of made me more aware of some if the positives of the cello (bigger strings therefore broader sound, a range that goes to, if not close to as high as a viola while going much deeper) while also showing me that the cello (and viola as well of course) both have the capacity to play more than just classical music. (Which I'm not a HUGE fan of, but will learn and play)

So, in terms of transport:

I'm aware that a cello is quite clunky to carry around, but I don't really plan on joining a band or group to play it, I mainly play for myself and family, so I wouldn't have to move it all that much.That being said I wouldn't mind knowing if it's that much of a big deal to put in the car and carry. (What's it like compared to carrying a guitar?)

I also have no interest in violin or double base, so please don't suggest either of them.

Just a few other questions:

Are there any particular brands I should lean towards depending on whether I get a viola or cello?

Are either of the two instruments more/less difficult to play than piano? (That is, to learn properly, not just play a tune or two by ear)

Are there any other questions I should be asking in relation to these two instruments?

Is there any further information the community would like to help answer this question?

I thank anyone who would lend the time to help me decide

-Brisingr