Better to use a new site or an old site for my script?

Hello guys,

I am willing to make deal with a new niche sites related to downloading and grabbing, etc.

I have an old site with 14k backlinks and I was wondering is it better to make a new subdomain for my niche or to buy a new domain for it?

The problem is that the site is international but the niche i would like to use only specific for a country so could I do that in google webmaster? to make a specific page for a country and my site for all countries?

If the niche is related to your main site then I would add it to your main site. Even if a few pages are in a different language - who cares. What you may want to do is put a small flag of the country you are targeting at the top of your home page of your international site. Anyone from that country will see it and click on their flag. People from other countries won't bother clicking on it. This approach will let you get your new stuff indexed quickly.

A subdomain off your main site is sort of like a new site. I personally wouldn't bother with that approach. Just my preference though.

If your international site is quite a bit different from your new niche then you should probably buy a new domain that includes your keyword.

Hope that helps.