Parked domains, Register one similar

Looking to register a domain name for a business, all the best ones have been parked.

The business is genuine and there are no businesses with a similar name, not sure why these domains have been parked.

Is it risky to register the .co / .net versions?

Has anyone had any experience of being on the other end of cybersquatting?

Don't go with .co / .net
The most important question: is your business name trademarked?
other than that a quick google search gives you these options:

1. Pay the fee for the domain name [the the cybersquatter]. This is a good choice if it will be cheaper and faster than dealing with litigation.
2. If companies do not want to give in and pay, they can use a cybersquatting lawyer and sue under the ACPA to obtain a court order to retrieve their trademarked domain name and possibly even money damages.
3. Companies can use the Internet Corporation of Assigned Names and Numbers system to arbitrate; however, this method cannot provide money damages to the company.