QUOTE(primrose @ Feb 14 2008, 02:49 PM)

I suggest you listen to some music with a viola in it (eg string quartets) and see whether you like the sound of it. Some (peculiar) people don't. You might just find that your parents are more tolerant of a viola. At least it doesn't have the E string, which can sound particularly awful in the hands of a beginner.
Most people who play the viola started with the violin anyway. You wouldn't find it hard to learn the alto clef, especially since you know the bass clef too. (Alto is right in between treble and bass). And, if you know someone who can help you with the violin, they can almost certainly help you with the viola too. It's basically just a big violin. (Or rather, a violin is just a small viola.)
I don't really know whether one is easier than the other. The stretches are obviously longer on the viola, though you can get small violas if you have small hands. And the greater distances mean that you have slightly more margin of error, intonation-wise. The viola part in an ensemble does tend to be a bit easier than the first violin part, though probably not the second violin part.
I wouldn't worry too much about being a late starter. They say it takes at least five years to learn to play the violin or viola moderately well, but you've got plenty of time. Even after five years, you'll have another 35 years of playing before you're as old as I was when I started.
Viola players tend to be more in demand than violinists, though it varies.
Violas and viola strings are slightly more expensive.
I think the most important thing is whether either of them is an instrument you really, really want to play.
I agree with everything Primrose has said. The viola makes a nicer sound at the start (and a nicer sound all together if I'm being thoroughly honest) and you will be in more demand when you can play reasonably well. If you learn the viola first, you won't have any trouble getting a tune out of a violin, either - and don't forget there are five stringed instruments available which would give you both a violin and a viola in the same instrument - the good quality ones sound very good indeed in both registers.
Personally, despite being a fiddle player, I would go for viola in your situation - it's a lovely mellow sound. I stuck with fiddle because the viola doesn't have much of a role in the music I play, and so I wouldn't have been in demand at all - the reverse is true in most other musical genres.
The best thing to do is listen to both a lot and decide which one you like the sound of best. That's the only one you'll really want to practise.
Have fun whatever you decide.