Welcome to the boards! At least one of the guys on here will be able to answer 99% of your questions 
And if you're on a budget, go with the bar-10. With some work, and an extra $30 of supplies from ace and a crafts store, it'll be performing nicely. The vsr-10 has better build quality, but unless you never plan on opening it, you'll need the extra money. After all, hobbies are expensive and you're just getting started
That's not to say that it'll perform up there with $500+ rifles that have the same tweaks done to them, but you'll be able to compete if your fieldcraft is up to par.
And if you're on a budget, go with the bar-10. With some work, and an extra $30 of supplies from ace and a crafts store, it'll be performing nicely. The vsr-10 has better build quality, but unless you never plan on opening it, you'll need the extra money. After all, hobbies are expensive and you're just getting started

That's not to say that it'll perform up there with $500+ rifles that have the same tweaks done to them, but you'll be able to compete if your fieldcraft is up to par.