Which solution assure me better chance to rank higher on the keyword of a brand?

So I want to rank on top 5 for the keyword of a brand, meaning the name of a company.

The keyword looks very easy.

Which solution do you think may work best for this:
- Buy a domain name with the brand in it (I can't do backlinking though)
- Build a 2.0 with the brand name as subdomain
- Build a google site
- Building it on Microsoft Azure

You can do all of them can't you? Although why can't you do backlinking... its pretty easy to do some manually if you can't afford it at the moment.